CHANGELOG

1.5.10

Compiler

Fixes

• KT-41078 Incorrect type substitution in contracts with type parameters
• KT-44770 JVM / IR: “IllegalArgumentException: Unrecognized Type: [null]” Jackson doesn't recognize type
• KT-45084 JVM IR: “NoSuchElementException: Sequence contains no element matching the predicate” when inline class is passed to lambda with >22 parameters
• KT-45779 JVM / IR: java.lang.NoSuchMethodError: ‘int java.lang.Integer.plus(int)’ caused by function reference
• KT-45941 JVM IR: local functions use generic type parameters of the outer class in the bytecode, which breaks Bytebuddy and MockK
• KT-46149 Generate synthetic classes for SAM adapters with erased instead of generic supertype
• KT-46189 JVM IR: tailrec function with capturing lambda in default parameter value leads to NoSuchMethodError at runtime
• KT-46214 JVM / IR: “IllegalStateException: No mapping for symbol: VALUE_PARAMETER INSTANCE_RECEIVER” on a suspend function in an inner class
• KT-46238 JVM IR: BootstrapMethodError in JDK 11+ on intersection type passed in arguments of SAM adapter where SAM interface's type parameter has a non-trivial upper bound
• KT-46259 JVM IR: local function for adapted function reference is not declared as ACC_SYNTHETIC
• KT-46284 JVM IR: “Unbound private symbol IrClassSymbol” on class reference to script class
• KT-46402 IllegalAccessError: “CapturedLambdaInterpreter (in unnamed module @0x71b06418) cannot access class jdk.internal.org.objectweb.asm.Type” caused by inline function with a suspend parameter in Maven project
• KT-46408 JVM IR: BootstrapMethodError due to missing bridge for subclass of generic Java interface
• KT-46426 JVM IR: Corrupted .class file when passing Array constructor reference as (inline) lambda
• KT-46455 OOM on parsing invalid code with string interpolation
• KT-46503 JVM IR: “AssertionError: Unexpected variance in super type argument: out @1”
• KT-46505 JVM IR: NullPointerException caused by a callable reference with nullable inline value class parameter
• KT-46512 JVM / IR: NoSuchMethodError on SAM conversion of a function reference
• KT-46515 IndexOutOfBoundsException: “Empty list doesn't contain element at index 0.” on bad variable name in 1.5.0
• KT-46516 JVM IR: “AnalyzerException: Expected I, but found R” on subclassing AbstractMutableList
• KT-46524 Cannot use unsigned literals with api-version < 1.5 even with opt-in
• KT-46537 JVM / IR: “IllegalStateException: No noarg super constructor for CLASS” caused by “No-arg” plugin with annotation on child class
• KT-46540 JVM / IR: AnalyzerException: Expected an object reference, but found J caused by java.function.Supplier
• KT-46554 JVM IR: “IllegalStateException: No mapping for symbol: VAR IR_TEMPORARY_VARIABLE” with value class constructor delegation call
• KT-46555 JVM IR: IllegalAccessError when using Java method reference
• KT-46562 Kotlin 1.5.0 generates non-serializable lambdas when they should be serializable
• KT-46568 JVM IR: “AssertionError: IrCall expected inside JvmStatic wrapper” on compiling protected static function with return type Nothing inside companion object of abstract class
• KT-46574 JVM / IR: ClassCastException caused by runBlocking awaiting call while returning Kotlin.Result type.
• KT-46579 JVM IR: “IllegalArgumentException: Sequence contains more than one matching element” for Java enum with overloaded values() static method
• KT-46584 JVM IR: Intrinsics.needClassReification (UnsupportedOperationException thrown). Property delegate provider crossinline lambda inlining/reification issue
• KT-46751 JVM / IR:“ClassCastException: java.lang.String cannot be cast to java.lang.Void” in extension function in Kotlin 1.5

IDE

• KT-45981 failed to analyze: java.lang.AssertionError: diagnostic callback has been already registered: Code analysis get stuck in AS 2020.3.1.14 & Kotlin v1.5.0-M2
• KT-46622 60+ second freezes with Kotlin plugin 1.5.0: GetModuleInfoKt.findJvmStdlibAcrossDependencies

IDE. Gradle Integration

• KT-46417 [UNRESOLVED_REFERENCE] For project to project dependencies of native platform test source sets

Libraries

• KT-46280 JvmRecord annotation missing constructor in common

Middle-end. IR

• KT-44013 NPE: When calling constructor of a function type while inheriting from it, despite it's an interface

Tools. Android Extensions

• KT-46590 Kotlin Android Extensions 1.5.0 generates bad writeToParcel() method for nullable Array types

Tools. Gradle

• KT-41142 Kotlin version conflict when using Kotlin Gradle plugins in pre-compiled script plugin
• KT-46353 Optimizations disabled in Gradle 7 for KAPT when generating sources
• KT-46368 Memory leak with 1.5.0-RC when building with Gradle
• KT-46689 Track -Xuse-old-backend flag usage

Tools. Gradle. JS

• KT-46006 KJS \ Gradle: Task without declaring an explicit or implicit dependency on jsGenerateExternalsIntegrated in Gradle 7
• KT-46162 KJS: Exported items unavailable on dev server
• KT-46331 KJS: With kotlin.js.webpack.major.version=4 browserXRun tasks fail

Tools. Parcelize

• KT-46567 Kotlin 1.5.0 parcelize compilation fails in new backend when using TypeParceller with nested generics

Tools. kapt

• KT-45532 Do not create Kapt stubs directory during configuration time

1.5.0

Backend. Native

• KT-42053 Support compiler caches for linux_x64
• KT-43690 Support compiler caches for ios_arm64

Backend. IR

• KT-42684 StackOverflowError on recursive inline arguments in inline fun

Compiler

New Features

• KT-28791 Kotlin serialization with inline classes
• KT-30222 Support JVM target version selection in Kotlin bytecode tool window
• KT-41884 Support ‘file’ target for JvmSynthetic annotation
• KT-43677 Support for Java records
• KT-43920 Support loading binary Java annotations on fields
• KT-44278 Generate SAM-converted lambdas and function references using ‘invokedynamic’ on JDK 1.8+
• KT-44650 Deprecate JVM target version 1.6
• KT-44787 Suspend functions in fun interfaces
• KT-44865 Allow to declare protected constructors in sealed classes
• KT-44869 Compiling sealed interface with version less than 1.5: error message from future could be provided

Performance Improvements

• KT-6336 Optimize generation of local functions
• KT-7307 Optimize infix call of String.plus
• KT-18692 Optimize ‘<optimizable_range> step x’ for-in loop
• KT-19978 Inefficient bytecode generated for function references undergoing Java SAM conversion
• KT-23565 OperationsMapGenerated.kt generates unreasonable amount of bytecode
• KT-23825 Tail suspend call utilizing elvis operator does not take advantage of suspend tail call optimization
• KT-23826 A suspend function on the right side of a returned || condition is not tail call optimized
• KT-25348 No compile time unsigned integer conversion when using hex literal
• KT-26060 Support a compiler mode to compile lambda expressions using invokedynamic instruction
• KT-26590 Do not generate create method for suspend lambdas if its arity >= 2
• KT-27427 Optimize nullable check introduced with ‘as’ cast
• KT-28246 Redundant boxing/unboxing isn't eliminated by the compiler in case of inline classes and javaClass intrinsic
• KT-30605 Constant folding doesn't evaluate inv() function
• KT-36845 Generate enum-based TABLESWITCH/LOOKUPSWITCH on a value with smart cast to enum in JVM_IR
• KT-39585 JVM BE generates redundant accessor calls when accessing static final field lifted from companion
• KT-40886 Old JVM BE unspills ACONST_NULL from continuation
• KT-42621 Kotlin binary size considerably larger for code extensively using stream API
• KT-44153 NI: Low Memory and IntelliJ hangs when quotes in split() are missed
• KT-45410 JVM / IR: Extreme performance regression on arithmetic operations inside a loop

Fixes

• KT-6007 Support changed return type of inlined generic function when lambda returns anonymous object
• KT-6055 Failed invoke plus assign on array element accessed via several args through local get/set convention extensions
• KT-6879 CompilationException when local classes hierarchy is placed within other local or inner declaration
• KT-8120 NoSuchMethodError on local class constructor call inside a local class
• KT-8199 “Cannot pop operand off an empty stack” for local class using a captured variable as default value for constructor parameter
• KT-10835 “AssertionError: Non-outer parameter incorrectly mapped to outer” when inlining object literal extending inner class
• KT-12790 Don't generate synthetic accessors for private inline function/properties
• KT-13213 IllegalArgumentException in ByteVector.putUTF8 on attempt to compile file with moderately long string literal
• KT-14628 “UnsupportedOperationException: Don't know how to generate outer expression” for nested class inheriting from inner class with a companion object
• KT-14833 JVM internal error: Augment assignment and increment are not supported for local delegated properties and inline properties
• KT-15403 Suspend operator get wrong code generated by BE (NoSuchMethodError)
• KT-15404 Suspend operator set wrong code generated
• KT-16084 Proguard can't find enclosing class of let closure inside apply closure
• KT-16151 Internal compiler error when using plusAssign operator with mutable map
• KT-16221 Support in/!in suspend operators
• KT-16282 “Cannot pop operand off an empty stack” for plusAssign with default parameters in setter operator
• KT-16445 java.lang.VerifyError: Bad type on operand stack when delegating an interface through a private reified function inside an object
• KT-16520 Invalid bytecode semantics for set call by convention with default parameters
• KT-16567 Inliner creates redundant objects on source inlining
• KT-16752 Delegating function interface to function reference does not work
• KT-17554 Incorrect cast to Unit generated on annotated when-expression with a single-branch if inside
• KT-17738 Java cannot extend class implementing kotlin.collections.Map
• KT-17753 Strange behavior of if and return statements
• KT-18583 “ISE: Recursive call in a lazy value” for generic sealed class with nested subclass in a when(this) with inferred return type
• KT-19861 “IllegalStateException: Label wasn't found during iterating through instructions” for plusAssign with safe call
• KT-20306 Make ‘when’ over an ‘expect’ enum class non-exhaustive
• KT-20869 kotlin.jvm.internal.DefaultConstructorMarker should be public
• KT-20996 IllegalStateException: Cannot get FQ name of local class: class in metadata serialization for common code
• KT-21014 Incorrect bytecode generated for ‘PrimitiveArray::size’
• KT-21092 Reference javaClass for generic property: “couldn't transform method node: get()”
• KT-21778 “IllegalStateException: Couldn't build context” for inline function inside an anonymous object
• KT-21900 VerifyError on equals on generic primitive type
• KT-22098 “UnsupportedOperationException: Don't know how to generate outer expression” on extension function call inside lambda in anonymous object super constructor call
• KT-22488 Bad line numbers generated for ‘&&’ expression
• KT-22972 A compiler bug(?) in Number class descendants
• KT-23619 Transform stateless singleton lambda during inline
• KT-23881 Declaration of lambda in inlined apply block holds reference to superfluous references causing leak
• KT-24135 Calling invoke on crossinline suspend lambda leads to no state-machine
• KT-24193 NoClassDefFoundError: java/lang/Cloneable$DefaultImpls on inheritance from Cloneable through an interface
• KT-24305 ClassNotFoundException when using Java reflection on local class in an inlined lambda
• KT-24564 Custom operator fun set on ByteArray resolves properly but is miscompiled
• KT-25400 “NoClassDefFoundError: kotlin/KotlinPackage” with Turkish system locale on macOS
• KT-26130 Incorrect method signature for a generic function with inline class as a type parameter upper bound
• KT-26360 “Method from super interface has a different signature” for Interface that extends both interfaces with and without @JvmDefault
• KT-26473 Error on compiling inline class with calls of super methods equals(), hashCode(), toString()
• KT-26474 VE “Bad type on operand stack” at runtime on calling toString() method of inline class with calls of super methods (toString(), equals(), hashCode()) inside
• KT-26592 Do not generate private suspend functions as synthetic package-private
• KT-27449 NoSuchMethodError for local suspend function with suspend lambda parameter with default value
• KT-27469 “Cannot pop operand off an empty stack” for compound assignment (plusAssign) with a vararg operator get
• KT-27825 Gradually prohibit non-abstract classes containing abstract members invisible from that classes (internal/package-private)
• KT-27830 “Incompatible stack heights” with suspend inline function in do while loop that executes suspend lambda
• KT-28042 “Cannot pop operand off an empty stack” for a bound callable reference of lambda inside inline function
• KT-28166 “Argument 1: expected I, but found R” for generic method with generic parameter or receiver with inline class upper bound
• KT-28331 Consider generating accessors for lateinit properties to avoid assertion on each call
• KT-28573 Inliner does not update references to transformed object
• KT-29331 “AnalyzerException: Argument 1: expected R, but found I” with local generic extension property called on Int receiver
• KT-29595 NoClassDefFoundError with inline reified function with lambda argument returning anonymous object
• KT-29802 Incorrect reification when the same type parameter name is used for different reified types
• KT-30041 “AnalyzerException: Expected an object reference, but found .” on nested suspend function calls outer suspend function
• KT-30066 Consider adding annotations to ConeKotlinType
• KT-30280 Inline class class literal gets unwrapped in annotation arguments
• KT-30402 Constant folding works incorrectly with unsigned arithmetics
• KT-30548 “java.lang.IndexOutOfBoundsException: Cannot pop operand off an empty stack” while compiling access to a private lateinit companion field
• KT-30629 java.lang.VerifyError: Bad type on operand stack when using a function reference to a generic property
• KT-30933 Inline function produces IllegalAccessError on property reference from different package
• KT-31136 “AnalyzerException: Argument 1: expected R, but found I” on x::javaClass when x is inline class object built around primitive type
• KT-31227 Prohibit using array based on non-reified type parameters as reified type arguments on JVM
• KT-31592 NoSuchMethodException when inlining public function accessing a protected static Java class member
• KT-31727 Object expression captures all variables used in constructor
• KT-32023 “AnalyzerException: Expected I, but found R” with inline suspend function used with callable reference
• KT-32115 NPE during initialization of enum class with delegated property
• KT-32153 “AnalyzerException: Expected an object reference, but found .” with recursive suspend local function
• KT-32351 ClassNotFoundException for anonymous object implementing interface inside a lambda with data class and inline methods
• KT-32384 Safe cast to generic type argument with inline class upper-bound throws NPE instead of ClassCastException
• KT-32579 java.lang.VerifyError: Bad type on operand stack on calling inner class of inherited class in super class when casting to inherited class
• KT-32749 “VerifyError: Call to wrong method” with inline function and accessing class field from anonymous object
• KT-32793 Generated code crashes by ClassCastException with local suspend function and inline class
• KT-32812 “AnalyzerException: Argument 1: expected R, but found I” invoking function with default parameter inherited by inline class
• KT-32821 Missing unboxing of inline class for complex hierarchy of suspend calls
• KT-33155 ClassNotFoundException for qualified this in anonymous object and as a result of inline function call
• KT-33173 Internal error: “AnalyzerException: Expected I, but found R” for supercall inside inline lambda from HashSet.remove implementation
• KT-33577 NoSuchFieldError with nested anonymous objects accessing outer instance property
• KT-33836 Wrong code generated for a local tailrec suspend function.
• KT-33873 ClassCastException invoking UByte setter function via reflection
• KT-34018 “Cannot pop operand off an empty stack” with inline lambda with callable reference
• KT-34186 JDK11: class file contains malformed variable arity method for vararg sealed class constructor
• KT-34202 IllegalAccessError on callable reference of function from multifile facade from standard library
• KT-34255 @JvmStatic tailrec function: “Cannot pop operand off an empty stack”
• KT-34507 Incorrect generated code for mutable collection stub methods in case of presence of functions with similar signature
• KT-34665 Possible index overflow in optimized “for” loop over withIndex()
• KT-34754 Flow builder: “AnalyzerException: Expected an object reference, but found .” with recursive suspend local function
• KT-34816 “AnalyzerException: Expected an object reference, but found I” on “this” in inline class member extension suspend function
• KT-34841 ClassNotFoundException when invoke param function inside anonymous object method
• KT-35008 “AnalyzerException: Expected an object reference, but found I” in inline class companion calling private constructor
• KT-35166 NoSuchMethodError at runtime with local property delegate on anonymous object referencing another anonymous object
• KT-35224 It's possible to pass non-spread arrays after arguments with SAM-conversion
• KT-35301 MethodInliner fails with “AssertionError: call doesn't correspond to object transformation info” for qualified this in SAM constructor used as parameter of anonymous object inside inline lambda
• KT-35419 Failed to generate expression: KtNamedFunction for local suspend tailrec function with receiver
• KT-35511 VerifyError: “Bad type on operand stack” after reification
• KT-35553 Kotlin compiler generates methods that always have line number 1 for Inline Classes
• KT-35725 “AssertionError: Couldn't find a context for a super-call” for super member call in property initializer of companion object
• KT-36420 ClassCastException with inline class Foo extending generic Comparable
• KT-36713 AnalyzerException: “Incompatible stack heights” with suspend and inline suspend functions
• KT-36794 Move $assertionsDisabled field to the top-level class
• KT-36853 IR: UninitializedPropertyAccessException on tailrec with object expression in default argument
• KT-36875 “RuntimeException: Trying to access skipped parameter” on synthetic local variable access from inline function
• KT-36916 AnalyzerException: Argument 1: expected I, but found R when using inline class with rxjava
• KT-36957 Exception during codegen: cannot pop operand off an empty stack (Nothing variable in string interpolation)
• KT-36984 SAM adapter classes should be generated as anonymous inner classes in JVM_IR
• KT-37704 Incorrect SMAP syntax
• KT-37716 “AssertionError: call doesn't correspond to object transformation info” with inline reified type parameter, anonymous object and lambda in constructor call
• KT-37972 IllegalAccessError on initializing property reference for a property declared in JvmMultifileClass with -Xmultifile-parts-inherit
• KT-38100 Support local delegated properties (not inlined) in new JVM default modes
• KT-38833 JVM: java.lang.ClassCastException when loop variable is nullable in for loop over unsigned progression
• KT-38849 Read-only variable initialized in non-inline lambda using contract callsInPlace EXACTLY_ONCE is not captured correctly in nested lambdas
• KT-38869 JVM BE produces invalid bytecode when inheriting from AbstractList and declaring methods that look like MutableList implementors (but they aren't)
• KT-38965 “UnsupportedOperationException: Don't know how to generate outer expression: Closure” with reference to local variable in block argument of anonymous object by delegation
• KT-39289 CCE in if-else inside annotated ‘if’ statement
• KT-39425 AbstractMethodError: “Receiver class does not define or inherit an implementation of the resolved method” using classes with complex Java and Kotlin inheritance hierarchies.
• KT-39434 IllegalAccessError with local delegated property in lambda in inlined function
• KT-39687 “Couldn't find captured this” when more than 3 inline functions are nested
• KT-39784 “IndexOutOfBoundsException: Cannot pop operand off an empty stack” caused by JvmOverloads annotation inside an inline class
• KT-40165 ClassCastException caused by SAM conversion used on a functional interface with suspended function
• KT-40179 “VerifyError: Bad type on operand stack” with parent class get extension function and child class set extension function which used inside child class plusAssign extension function
• KT-40277 Fix generic types in special bridge methods
• KT-40308 NoSuchFieldError for multiple delegated extension properties with the same name in a companion object
• KT-40338 NoSuchFieldError on property without backing field that is called as function reference
• KT-40392 Deprecate JvmDefault annotation and old -Xjvm-default modes
• KT-40396 NI: Exceptions when ambiguous type argument and generic invoke
• KT-40510 “AssertionError: DELEGATION slice must override something” for ByteBuffer delegation
• KT-40601 VerifyError: “interface method reference is in an indirect superinterface” when calling @JvmDefault suspend method
• KT-40809 “Couldn't find captured field” compiler error with local function with recursive call through method reference
• KT-41056 Increase stub version due to new “contract” keyword
• KT-41105 IllegalStateException: ‘Couldn’t find declaration file ' with inline delegate declared in another file
• KT-41165 “IllegalStateException: Concrete fake override public final fun” when an enum class inherits an interface with a variable ‘name’ or ‘ordinal’
• KT-41222 “IllegalStateException: Concrete fake override public final fun” when a class property is inherited as merged ‘var’ from ‘val’ and ‘var’ from parent abstract class and interface properties
• KT-41255 JDK 11: “VerifyError: Bad type on operand stack” with long function body with annotated when expression
• KT-41427 NoSuchMethodError caused by implementation by delegation to function reference
• KT-41508 ClassNotFoundException caused by object with overridden function inside a lambda with safe cast receiver
• KT-41750 Inline classes: ClassCastExceptionError when calling .withIndex() on Iterator over Array
• KT-41758 Deprecate kotlin.Metadata.bytecodeVersion and avoid using it in the compiler
• KT-41770 AssertionError: “Asm parameter types should be the same length as Kotlin parameter types” cause by fun interface
• KT-41874 “IllegalStateException: Couldn't obtain compiled function body” on extension delegated property with inline operator getValue in a different file
• KT-41917 [FIR] Incorrect calculating property type for override from intersection scope
• KT-42012 IllegalAccess to protected field instead of getter
• KT-42017 “AssertionError: Unsigned type expected: UInt?” during codegen when a variable of nullable unsigned type is checking for presence in the range
• KT-42032 “AnalyzerException: Expected I, but found R” while using Flow.reduce() with suspend function reference
• KT-42034 ArrayIndexOutOfBoundsException in PopBackwardPropagationTransformer on external override of function in inline class
• KT-42064 “Parameter specified as non-null is null” with default value of the parameter in operator fun
• KT-42069 JVM IR: -Xreport-output-files doesn't report any source files for META-INF/*.kotlin_module files
• KT-42083 AbstractMethodError when ‘remove’ with irrelevant generic parameter but matching JVM signature is present in Kotlin collection class
• KT-42092 JVM / IR: “AnalyzerException: Argument 1: expected R, but found J” when trying to add to ArrayList the result of a function applied to int
• KT-42175 Psi2ir: “AssertionError: Undefined parameter referenced: ” on augmented assignment on this in a BuilderInference lambda
• KT-42179 Platform declaration clash when extending abstract Java class implementing ‘java.util.Collection’ by abstract Kotlin class implementing Kotlin Set or List
• KT-42321 JVM IR: do not cast integer value based on the type of a literal receiver of an operator call
• KT-42337 NoSuchMethodError in JVM backend with inheritance of private functions in the interface
• KT-42404 “Supertypes of the following classes cannot be resolved” in Rider project
• KT-42472 No TYPE_INFERENCE_UPPER_BOUND_VIOLATED for Delegated Properties do not check types (in Kotlin 1.4.10)
• KT-42487 “IndexOutOfBoundsException: Cannot pop operand off an empty stack” caused by USELESS_IS_CHECK of Double type
• KT-42533 (N until MIN_VALUE).reversed() should be an empty progression in for loops
• KT-42588 “IllegalStateException: Concrete fake override public open fun” caused by val override with var with delegation.
• KT-42634 Different bridges and abstract stubs behavior in abstract class implementing Map<K, String> in JVM and JVM_IR
• KT-42635 ClassCastException with inline class in for loop
• KT-42662 AbstractMethodError when using partially specialized generic Map class
• KT-42694 @get:Synchronized causes the JVM getter method not to be generated
• KT-42753 “VerifyError: Bad invokespecial instruction: interface method reference is in an indirect superinterface” with jvm-default=all
• KT-42879 JVM: Declaration clash in fun interface implementation returning an inline class
• KT-42900 “VerifyError: Bad return type” incorrect bytecode when a property and an extension property in inline class have the same names
• KT-42946 FIR2IR: Fix super-calls to Java overrides of special built-in
• KT-42971 JVM: “AssertionError: Unsigned type expected: T” with UInt loop range
• KT-42990 “AssertionError: Next value after NEW should be one generated by DUP” caused by extension properties with accessors annotataed as @JvmStatic
• KT-43034 AssertionError: Compiler fails with complicated tailrec + inline case
• KT-43048 JVM_IR: Implement coroutines state clearing
• KT-43050 JVM IR: incorrect mangling for method with type parameter with inline class bound in the signature
• KT-43059 Different bridges behavior in class implementing Map<String, String> in JVM and JVM_IR
• KT-43063 Redundant DefaultImpls delegate is generated in old JVM backend on explicit “duplicate” inheritance from interface
• KT-43069 JVM: incorrect generic signature for method with implicit return type Nothing overriding a method from Collection
• KT-43099 Tailrec call in not tail-call position leads to internal compiler error
• KT-43106 JVM: custom remove in Iterator subclass results in a synthetic bridge
• KT-43120 JVM: “Expected an object reference, but found .” caused by function which is passed as reference to suspend parameter
• KT-43167 JVM IR, serialization: “No mapping for symbol: VALUE_PARAMETER INSTANCE_RECEIVER” with data class containing property defined in body
• KT-43255 Verify error when inheriting from an abstract class implementing Collection with stub-like method in superclass
• KT-43303 NI: False negative TYPE_INFERENCE_UPPER_BOUND_VIOLATED when inferred type argument is not a subtype of type parameter upper bound
• KT-43333 AbstractMethodError when calling ‘toArray’ from Java on a Kotlin Collection with custom internal ‘toArray’
• KT-43334 AbstractMethodError when calling ‘remove’ from Java on a Kotlin Collection with custom internal ‘remove’
• KT-43342 [FIR2IR] No getter or backing field found for delegated member call
• KT-43347 [FIR] Synthetic setter with unmatched parameter type isn't found
• KT-43401 JVM_IR. Additional synchronized flag on JvmOverloads-generated adapter for Synchronized function
• KT-43405 Turkish locale, Linux Mint: “NoSuchMethodError: ‘int[] kotlin.jvm.internal.Intrinsics$Kotlin.intArrayOf(int[])’” with intArrayOf function call
• KT-43460 JVM: redundant private setter is generated in case of multifile facade
• KT-43473 “VerifyError: Bad type on operand stack” caused by operator get with optional argument in superclass when called via square brackets on subclass
• KT-43518 JVM_IR. Additional strictfp flag on JvmOverloads-generated adapter for Strictfp function
• KT-43569 FIR: inapplicable candidate(s): kotlin/collections/set
• KT-43616 [FIR] Nullable type parameter-based type after merge in if
• KT-43669 FIR: No real overrides for FUN IR_EXTERNAL_DECLARATION_STUB
• KT-43682 Inline extension method of a multifile library inline class not found
• KT-43687 FIR: UnusedChecker does not take annotation arguments into account
• KT-43688 FIR: unused checker doesn't handle invokes properly
• KT-43749 “UnsupportedOperationException: Don't know how to generate outer expression: Closure” caused by Flow and collect method with function reference as a parameter
• KT-43812 JVM IR: SAM wrapper class with generic supertype mentions missing type parameter in the signature
• KT-43832 JVM IR: missing bridges for inheritance of class from interface in a complex generic diamond hierarchy
• KT-43851 JVM IR: function call returning object instance is removed during constant propagation
• KT-43864 JVM: “Assertion error after mandatory stack transformations: incorrect bytecode” with lateinit property of type T, which has a primitive type upperbound
• KT-43887 Problem with FunctionReferenceLowering$FunctionReferenceBuilder in kotlin native
• KT-43912 JVM internal error: Augment assignment and increment are not supported for local delegated properties and inline properties
• KT-43915 Back-end (JVM) Internal error: wrong bytecode generated for default method
• KT-43938 NSME when calling ‘kotlin.Number’ methods on instance of Java class extending Kolin abstract class extending ‘kotlin.Number’
• KT-43942 org.jetbrains.kotlin.codegen.CompilationException: Back-end (JVM) Internal error: Failed to generate function
• KT-43949 FIR: unresolved callable reference as lambda return
• KT-43983 IllegalStateException: “Couldn't obtain compiled function body for public final suspend inline fun” after moving inline extension function to library
• KT-43984 FIR: recursion in overridden symbols
• KT-43984 FIR: recursion in overridden symbols
• KT-44010 FIR: Inapplicable constructor due to an unresolved reference
• KT-44030 FIR2IR: uncached type parameters in delegated property
• KT-44032 FIR2IR: uncached type parameters in Java field
• KT-44050 FIR: anonymous object as IR parent
• KT-44054 FIR2IR: incorrect IR origin for substituted override function
• KT-44058 CompilationException: open suspend fun with @JvmStatic in open class companion
• KT-44069 please remove deprecated usages
• KT-44066 FIR Java: override ambiguity with vararg value type
• KT-44114 CompilationException when inlining a extension suspend function declared in interface companion with ‘this’ reference to extension receiver
• KT-44131 “UnsupportedOperationException: Don't know how to generate outer expression: Closure” when using suspend lambda and a function reference
• KT-44140 JVM IR: compilation of kotlin.Result crashes with IOOBE while generating toString-impl
• KT-44141 JVM IR: “ISE: There should be underlying type for inline class type” on usage of type parameter with Result upper bound inside a lambda
• KT-44192 Allow a greater number of constants in an enum class
• KT-44202 “ClassCastException” when getting delegated property with inline class and Any/Any? type
• KT-44210 KJS / IR: “AssertionError: Undefined parameter referenced: defined” caused by plus assign operators in build blocks
• KT-44233 [IR] Collection Stub generation not correctly considering java.util Collection iterators
• KT-44234 Private companion property with explicit setter generates invalid bytecode
• KT-44269 “[TAILREC_ON_VIRTUAL_MEMBER_ERROR] Tailrec is not allowed on open members” with Spring annotation and private tailrec function
• KT-44284 Make Kotlin binaries publicly unavailable (set KotlinCompilerVersion.IS_PRE_RELEASE = true)
• KT-44316 ReenteringLazyValueComputationException when analyzing complex lazy delegate
• KT-44347 Back-end (JVM) Internal error: Couldn't transform method node for suspend function with wrong local for Continuation
• KT-44368 “IllegalStateException: Error type encountered” when inlining ‘invoke’ operator without enough information on type variable
• KT-44412 JVM IR backend fails to compile break in condition of do while
• KT-44420 False NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATION with 1.4.30-RC
• KT-44429 JVM IR: unnecessary integer unboxing leads to NPE when using mockito-kotlin
• KT-44439 Type inference of generic types failing java interop
• KT-44440 Too many Nothings in inferred type
• KT-44471 Fix failing script tests after switching to 1.5
• KT-44474 Compiler expects sealed type inheritors from platform specific source-sets in when expression in common source-set
• KT-44483 JVM IR: CCE on calling generic vararg function reference with Array expected type
• KT-44527 Suspend function with kotlin.Result: ClassCastException class kotlin.Result cannot be cast to class ...
• KT-44529 Inline class calls wrong iterator method in for loop
• KT-44533 JVM IR: ClassFormatError on synthetic $suspendImpl method generated in interface for a @JvmDefault function
• KT-44540 Regression in 1.4.30 in intellij-community: type mismatch for generic function call with generic Java class
• KT-44546 NI: changed variable fixation order (that can lead to changed resolution)
• KT-44550 KotlinBinaryClassCache leaks Kotlin plugin classloader on plugin unload
• KT-44563 Type Inference loosing type annotations in lambda type expectation for function calls with block parameters
• KT-44583 “Supertypes of the following classes cannot be resolved” error message gives no context
• KT-44627 JVM IR: ACCIDENTAL_OVERRIDE when overriding a generic field where the type parameter has a primitive bound
• KT-44631 “IndexOutOfBoundsException: Cannot pop operand off an empty stack” caused by a default param in inner class constructor which uses method or field from receiver
• KT-44647 “IllegalAccessError: class TestKt tried to access private method” with String Builder get and inc operator
• KT-44651 JVM / IR: “IllegalStateException: Illegal type substitutor” with if-else inside class constructor argument inside another if-else
• KT-44660 Internal inline functions in companion object with inline class return type fails compilation
• KT-44671 JVM_IR: ClassCastException: Result$Failure cannot be cast to Result with multithreaded coroutines
• KT-44703 JVM / IR: “IllegalStateException: Unhandled special name in mangledNameFor” caused by a reference to inline class inside interface's companion with lazy initialization
• KT-44712 JVM / IR: Behavior change after enabling with Mockito
• KT-44714 Debugger / Coroutines: Local variables are trimmed out too aggressively
• KT-44722 JVM IR: ClassCastException with inline class, let and bound function reference
• KT-44726 JVM IR: Incorrect KType nullability for platform type reified as non-null
• KT-44781 JVM IR: java.lang.NoSuchFieldError: $noName_0 when calling a crossinline lambda within a suspending lambda
• KT-44798 JVM IR: Inherited platform declarations clash for class implementing both List and Set
• KT-44801 1.4.30 JVM IR: Unbound symbols not allowed with anonymous object
• KT-44803 FIR bootstrap: incorrect nullability is set for type alias-based type
• KT-44827 Non-existing outer class is written in anonymous class for SAM wrapper in inline lambda with capture
• KT-44837 JVM / IR: ClassCastException with Result object when it is used by a generic method in a suspend call
• KT-44875 JVM_IR. hashCode call is generated on interface target in fun interface equality
• KT-44878 JVM_IR: “IllegalStateException: Unexpected types” when checking non-nullable variable is in range between nullable ones with smart-cast
• KT-44926 MPP: Actual typealias to compiled inline class incompatible with expect inline class
• KT-44947 Sealed interfaces: Sealed fun interface leads to “NoWhenBranchMatchedException”
• KT-44993 JVM IR: VerifyError on getfield with Kotlin generic field and elvis operator
• KT-45008 JVM IR: hashCode is generated as invokeinterface if smart cast to interface is present
• KT-45011 JVM / IR: “AssertionError: Unbound symbols not allowed”
• KT-45022 IR: “AssertionError: Undefined variable referenced” from psi2ir caused by plusAssign operator of object
• KT-45064 JVM IR: “java.lang.AssertionError: SyntheticAccessorLowering should not attempt to modify other files!” with member reference to property in another file with private setter
• KT-45067 “IllegalArgumentException: Wildcard mast have a bound for annotation of WILDCARD_BOUND position” with BEAM SDK 2.27
• KT-45069 JVM / IR: New SAM conversions mode fails when converting from Unit to Any
• KT-45131 JVM / IR: “RuntimeException: Lambda, SAM or anonymous object should have only one constructor” caused by inline class that type cast to reified type parameter inside lambda in inline function
• KT-45139 Inline class: AssertionError: Expected top level inline class
• KT-45166 JVM / IR: “AbstractMethodError: Receiver class does not define or inherit an implementation of the resolved method of interface” caused by interface with suspend function
• KT-45187 JVM / IR: ClassCastException caused by substituting generic type of vararg parameter with java.lang.Void
• KT-45195 JVM IR: annotation methods are generated as default interface methods if allopen is used
• KT-45243 “IllegalStateException: Lambdas shouldn't be visited by ESExpressionVisitor” caused by lambda inside kotlin.test.assertNotNull
• KT-45259 JVM: ClassCastException caused by Result as lambda parameter type
• KT-45292 AssertionError with recursive inline extension property
• KT-45300 Deprecate super calls in public-api inline functions
• KT-45409 Rename jspecify annotations’ package and default not null annotation
• KT-45446 JVM / IR: NullPointerException caused by unreachable code and comparison
• KT-45721 JVM / IR: “Unbound symbols not allowed” caused by class reference in sequence lambda
• KT-45853 JVM / IR: “Accidental override” caused by inheriting Throwable.getCause from Java interface
• KT-45861 Turning warnings into errors for calls with type parameters annotated by @OnlyInputTypes
• KT-45865 JVM IR: “VerifyError: Bad type on operand stack” with enumValueOf on a value from a list of strings
• KT-45868 JVM IR: ClassCastException with SAM function in init block when SAM is generated via invokedynamic
• KT-45920 JVM IR: “Accidental override” on redefining get() in custom Map class
• KT-45934 JVM IR: “java.lang.IllegalStateException: Function has no body” for class implementing interface by delegation
• KT-45945 JVM / IR: “AssertionError: Unexpected variance in super type argument” with contravariance and intersection types
• KT-45963 JVM / IR: “AbstractMethodError: Receiver class does not define or inherit an implementation of the resolved method” in Dokka tests
• KT-45967 JVM IR: “IllegalAccessError” with invokedynamic to Java SAM over callable reference to private function
• KT-45982 Wrong subtyping result on captured types with postponed type variables
• KT-46007 JVM / IR: “ClassCastException: kotlin.Unit cannot be cast to java.lang.String” caused by default suspend function in interface
• KT-46060 JVM IR: NullPointerException from RangeContainsLowering when contains is a @JvmStatic function in object
• KT-46069 JVM IR: unbound type parameter on generic bound adapted function reference
• KT-46092 JVM IR: AssertionError “Array type expected: @[FlexibleNullability] kotlin.CharArray?” on super call to Java constructor with primitive vararg
• KT-46104 The message on inline -> value class migration should not say that inline classes are deprecated
• KT-46131 Kotlin 1.5.0-RC errors when reading class file
• KT-46160 JVM IR: IllegalAccessException at runtime for member reference to JvmMultifileClass member from stdlib
• KT-46186 Type inference regression in Kotlin 1.5 with constrained generic return types

Docs & Examples

• KT-45884 Incorrect description for JVM toUpperCase method

IDE

• KT-33233 Use dependency of library to build built-ins in IDE, instead of loading them from the current classloader
• KT-34023 kotlin.KotlinNullPointerException at org.jetbrains.kotlin.backend.common.FunctionsFromAnyGenerator.getPrimaryConstructorProperties(FunctionsFromAnyGenerator.kt:66)
• KT-35947 KFunctionN.call is unresolved in IDE in Kotlin/JVM project
• KT-37702 Code analysis speed: on-the-fly analysis diagnostics reporting
• KT-41048 [FIR-IDE] Properly implement methods in KtFirPackageScope
• KT-41671 Missing nullability information in properties using type inference from get()
• KT-43824 KtLightClassForSourceDeclaration#isInheritor works in a different way than java implementation
• KT-44128 IDE: Kotlin JVM record has incorrect property accessors as seen from Java
• KT-44487 MPP, IDE: No error in IDE when sealed class inheritor from common source-set is not used in exhaustive when expression in platform source-set
• KT-45254 Highlighting for files with certain errors appears only on second opening
• KT-46097 Light classes: Incomplete nullability information for a getter method of a kotlin property defined in private constructor

IDE. Decompiler, Indexing, Stubs

• KT-43699 IDE: Unresolved extension method from Java code for simple class with typealias and generics (IllegalStateException: Unknown type parameter)
• KT-44756 Infinite “UpToDateStubIndexMismatch: PSI and index do not match.” with IDEA 2021.1 EAP upon attempt to open “org.gradle.configurationcache” even they seem to be the same

IDE. Gradle Integration

• KT-37127 Implement precise importing of platforms of root source sets (commonMain/commonTest) when hierarchical multiplatform support is enabled
• KT-42048 KJS / Gradle integration: Could not determine the dependencies of task ‘:webApp:testPackageJson’ in Android Studio 4.2 Canary 11

IDE. Gradle. Script

• KT-46215 Dead lock on closing project during the import in IJ211 through ScriptDefinitionsManager

IDE. Inspections and Intentions

• KT-23824 Return lifted out of if condition causes suspend tail call optimization to no longer apply
• KT-38155 Lift assignment out of ‘if’ produces type mismatch without manually adding a semicolon
• KT-44821 IDE: False positive NO_ELSE_IN_WHEN caused by sealed class and when in another module
• KT-46088 [IDEA] Incorrect behavior of replace inline class with value class intention

IDE. Misc

• KT-44675 Incorrect reference to resource into 202 plugin

IDE. Refactorings

• KT-44079 Sealed Interfaces: Move refactoring should warn about violation of hierarchy restrictions
• KT-44839 Sealed interfaces: move refactoring warnings works with “more freedom for sealed classes” rules for language level < 1.5

IDE. Script

• KT-43288 Allow push notifications about script configuration /dependencies changes via the ScriptDefinitionsProvider EP

JavaScript

• KT-39272 KJS / IR: Can't use javascript keywords as JsName
• KT-41650 JS IR BE: default should be a reserved identifier
• KT-42176 KJS / IR: Interface default method in sub-interface not resolved correctly from extension on super-interface
• KT-44103 [JSIR] TypeError when bumping from 1.4.20 to 1.4.30-M1
• KT-44180 KJS / IR: NPE in ConstTransformer of compileDevelopmentExecutableKotlinJs/compileProductionExecutableKotlinJs tasks
• KT-44415 Kotlin/JS with IR and kotlin-react: “too much recursion” error in runtime in browser
• KT-44433 KJS IR: support function interfaces with suspend member
• KT-44469 KJS / IR: Incorrect export functions with bridges
• KT-44718 MPP/ KJS: “IllegalStateException: Unsupported operation” with serialization plugin and incremental compilation
• KT-44796 KJS / IR: default parameter of function with @JsName leads to “RangeError: Maximum call stack size exceeded”
• KT-45059 KJS / IR: Add possibility for runtime diagnostics of DCE result

Libraries

• KT-12109 Add stdlib method that combines mapNotNull() and first/firstOrNull()
• KT-25571 Make random implementations serializable
• KT-26234 Floored division and remainder function for numeric types
• KT-32996 kotlin.test: add assertContentEquals for comparing content of arrays, iterables, sequences
• KT-39177 Make CharCategory available in common multiplatform code
• KT-40225 Support adding kotlin-test as a single dependency, as it should be with a multiplatform library
• KT-42071 Strict version of String.toBoolean()
• KT-42720 Kotlin ArrayDeque on JVM: provide optimized toArray method
• KT-42840 Commonize and generalize String.contentEquals that is currently JVM-only
• KT-43772 Kotlin/Native unfinished workers detected.
• KT-44168 Prevent storing NaN and negative zero in kotlin.time.Duration
• KT-44369 Commonize Char.titlecaseChar() and Char.titlecase() that are currently JVM-only
• KT-44783 Add IS_VALUE flag for value classes to kotlinx-metadata-jvm
• KT-44815 Remove kotlin-annotations-android and JVM compiler support for @ParameterName/@DefaultValue/@DefaultNull
• KT-45213 Update Unicode version used in K/N for Char and String case conversion functions

Middle-end. IR

• KT-43831 Compilation failed, IrSimpleFunctionPublicSymbolImpl is already bound
• KT-44100 KJS / IR: Top level declarations added in IR plugin are not referenceable from other modules
• KT-45170 IR: “AssertionError: Single expression value for GET_OBJECT” caused by inc operator of field inside scope function inside object

Native

• KT-42446 Native: SIGSEGV in Kotlin_Array_get on linuxArm64
• KT-43502 [K/N] relocation R_X86_64_PC32 cannot be used against symbol __environ; recompile with -fPIC
• KT-44295 1.4.21 Kotlin native ndk compiler crash
• KT-44774 ld fails with CALL16 reloc at 0x48f00 not against global symbol (Linux MIPS)
• KT-44746 Different hashCode() results for Kotlin/Native stdlib

Native. C and ObjC Import

• KT-44824 cinterop tool no longer appends .klib to produced klibs

Native. C Export

• KT-36639 MPP: Build ios “staticLib” or “sharedLib” binary failed if interface contains member extension function
• KT-41725 Dynamic library doesn't load on raspberrypi

Native. ObjC Export

• KT-44549 In the Xcode debug session, call stack is missing a frame when the iOS app fails

Native. Platforms

• KT-45094 Fail to compile Kotlin Native sources under Oracle Linux 7

Reflection

• KT-44594 Avoid using unnecessary array types reflection in kotlin-reflect
• KT-44782 Add KClass.isValue to kotlin-reflect

Tools. Ant

• KT-16227 Ant task: do not include runtime by default if destination is a jar
• KT-44293 Support fork mode in kotlinc Ant task

Tools. CLI

• KT-17344 Include kotlin-reflect to resulting jar if “-include-runtime” is specified
• KT-43220 -include-runtime should add .kotlin_builtins to the output
• KT-43704 Illegal reflective access by com.intellij.util.ReflectionUtil to method java.util.ResourceBundle.setParent(java.util.ResourceBundle)
• KT-44078 Do not include module-info.class of kotlin-stdlib.jar to the resulting jar with -include-runtime
• KT-44232 CLI: do not pass -noverify to java process starting from JDK 13
• KT-45566 JDK 16 - e: java.lang.NoClassDefFoundError: Could not initialize class org.jetbrains.kotlin.com.intellij.pom.java.LanguageLevel

Tools. CLI. Native

• KT-43874 Native / CLI: provide a way to show difference between Jvm and Native compilers

Tools. Compiler Plugins

• KT-45783 Serialization: “AnalyzerException: Expected an object reference, but found I” caused by JvmInline and Serializable annotations

Tools. Gradle

• KT-31027 java.lang.NoSuchMethodError: No static method hashCode(Z)I in class Ljava/lang/Boolean; or its super classes (declaration of ‘java.lang.Boolean’ appears in /system/framework/core-libart.jar)
• KT-43605 Kotlin Gradle Plugin 1.4.20 undeclared system property reads cause problems with Gradle configuration cache enabled
• KT-44204 Kotlin Gradle Plugin 1.4.21 makes impossible to use ANTLR in other plugins
• KT-44361 Gradle: deprecate options includeRuntime, noStdlib, noReflect
• KT-44462 Kotlin Gradle plugin creates compile configuration with Gradle 7.0
• KT-44834 Gradle Kotlin DSL: Add languageSettings configuration lambda without apply call
• KT-44949 Compatibility with Gradle 7.0
• KT-44957 gradle - target.compilations seems to be deprecated
• KT-45340 Update minimal supported version of Kotlin Gradle Plugin to 6.1

Tools. Gradle. JS

• KT-43237 KJS: -jsLegacy Naming Convention is incompatible with NPM
• KT-43869 Error in webpack configuration not displayed
• KT-44614 Update Node.JS and Yarn versions
• KT-44616 Kotlin/JS: IR backend with React: “Uncaught TypeError: _this__0 is undefined” runtime error in browser
• KT-45574 Sync Kotlin/JS compile tasks into one folder (build/js/packages//kotlin)

Tools. Gradle. Multiplatform

• KT-42098 Commonizer is re-launched for every included Gradle build
• KT-43116 Merge together MultiplatformHighlightingTest and MultiplatformAnalysisTest
• KT-44322 KotlinTargetComponent maintenance for -sources.jar
• KT-44900 Support gradle configuration cache with kotlin.multiplatform plugin

Tools. Gradle. Native

• KT-46122 kotlinx-serialization and kotlinx-datetime can't be built with 1.5.0-RC

Tools. JPS

• KT-13631 Compilation fails on Turkish locale because of locale-sensitive uppercasing
• KT-44644 Mark all @JvmMultifileClass parts compiled in the previous round as dirty in the JPS plugin, similarly to how it’s done in the Gradle plugin

Tools. Scripts

• KT-45194 KT: Generate Kotlin Entities script: it doesn't work
• KT-44580 Scripts: Unable to set new file annotation hooks after first snippet compilation

Tools. kapt

• KT-43686 KaptWithoutKotlincTask should use @CompileClasspath for kotlinStdlibClasspath for cache relocateability.
• KT-44130 KAPT changes field order in 1.4.30-M1
• KT-44909 Kapt: ReenteringLazyValueComputationException without stacktrace caused by when expression with sealed class function without explicit return type
• KT-45168 KAPT: Java stubs generated for Kotlin files generated by annotation processors

1.4.32

IDE

• KT-43824 KtLightClassForSourceDeclaration#isInheritor works in a different way than java implementation
• KT-45287 LightClasses: KtLightSimpleModifierList is no more a parent of KtLightAnnotationForSourceEntry
• KT-45291 LightClasses: can't get annotations for constructor val-parameter
• KT-45417 ULC leakage of primitive type annotations

Tools. CLI

• KT-44758 kotlin-compiler-embeddable dependency includes unshaded fastutil package
• KT-45007 Concurrent Kotlin script compilation/execution results in NullPointerException in KeyedExtensionCollector.getPoint()

1.4.31

Compiler

• KT-39776 2020.3+: Unresolved reference to Kotlin stdlib function

IDE. Gradle Integration

• KT-44845 After update to Kotlin 1.4.30 all external dependencies is unresolved in IDE with kotlin.mpp.enableGranularSourceSetsMetadata=true

IDE. Gradle. Script

• KTIJ-11137 build.gradle.kts: Fatal error during save/load standalone scripts settings
• KTIJ-898 Unable to import with Kotlin DSL buildscript - NullPointerException in KotlinDslScriptModelProcessorKt.toListOfScriptModels

IDE. Multiplatform

• KTIJ-1200 KotlinIconProviderKt.addExpectActualMarker takes up to 180+ seconds

IDE

Fixes

• KT-44697 New JVM IR backend notification - narrow its triggering to Kotlin projects
• KT-44523 IDE notification for trying new JVM backend
• KTIJ-696 Freeze during startup of IDEA with intellij project with Kotlin (211-1.4.10-release-IJ1440)

1.4.30

Android

• KT-42383 HMPP: Bad IDEA dependencies: Missing dependency from p1:jvmAndAndroid to p2:jvmAndAndroid

Backend. Native

• KT-38772 Native: support non-reified type parameters in typeOf
• KT-42234 Move LLVM optimization parameters into konan.properties
• KT-42649 IndexOutOfBoundsException during InlineClassTransformer lowering
• KT-42942 Native: optimize peak backend memory by clearing BindingContext after psi2ir
• KT-43198 Native: support init blocks inside inline classes

Compiler

New Features

• KT-28055 Support init blocks inside inline classes
• KT-28056 Consider supporting non-public primary constructors for inline classes
• KT-41265 Support noarg compiler plugin for JVM IR
• KT-42094 Allow open callable members in expect interfaces
• KT-43129 FIR: Support OverloadResolutionByLambdaReturnType
• KT-43592 Promote JVM IR compiler backend to Beta
• KT-43919 Support loading Java annotations on base classes and implementing interfaces' type arguments
• KT-44021 Enable JVM IR backend by default in 1.5

Performance Improvements

• KT-41352 JVM IR: reduce bytecode size in for loops and range checks with ‘until’ by not using inclusive end
• KT-41644 NI: Infinite compilation
• KT-42791 OutOfMemoryError on compilation using kotlin 1.4 on a class with a lot of type inference
• KT-42920 NI: Improve performance around adding constraints

Fixes

• KT-11454 Load annotations on TYPE_USE/TYPE_PARAMETER positions from Java class-files
• KT-11732 Verify error for generic interface method invocation with default parameters
• KT-14612 “ISE: Recursive call in a lazy value” during processing of a (weakly) recursive type alias
• KT-18344 Upper bound of a typealias type parameter is not reported correctly if it contains the typealias itself
• KT-18768 @Notnull annotation from Java does not work with varargs
• KT-20548 java.lang.IllegalStateException: Illegal class container on simple Java code parsing
• KT-22465 Excessive synthetic method for private setter from superclass
• KT-23816 Inline classes: constants and annotations
• KT-24158 AE: No receiver found on incomplete code with $-signs
• KT-24392 Nullability of Java arrays is read incorrectly if @Nullable annotation has both targets TYPE_USE and VALUE_PARAMETER
• KT-26229 Lambda/anonymous function argument in parentheses is not supported for callsInPlace effect
• KT-29735 KNPE at KtEnumEntrySuperclassReferenceExpression.getReferencedElement with explicit type argument inside enum member constructor
• KT-31389 ClassFormatError with companion object in annotation with @JvmStatic
• KT-31907 ISE: UNIT_EXPECTED_TYPE on parsing array literal inside lambda with Unit return type
• KT-32228 Inconsistent boxing/unboxing for inline classes when interface is specialized by object expression
• KT-32450 Inline class incorrectly gets re-wrapped when provided to a function
• KT-35849 Missing nullability assertion on lambda return value if expected type has generic return value type
• KT-35902 Kotlin generates a private parameterless constructor for constructors taking inline class arguments with default values
• KT-36399 Gradually support TYPE_USE nullability annotations read from class-files
• KT-36769 JVM IR: Missing LVT entries for inline function (default) parameters at call site
• KT-36982 JVM IR: SAM adapter classes are generated as synthetic
• KT-37007 JVM IR: extraneous property accessors are generated in multifile facade for InlineOnly property
• KT-37317 [FIR] Add support of extension functions in postponed lambda completion
• KT-38400 FIR: interface abstract is preferred to Any method in super resolve
• KT-38536 JVM IR: bound adapted function references are not inlined
• KT-38656 FIR: determine overridden member visibility properly
• KT-38901 FIR: Make behavior of integer literals overflow consistent with FE 1.0
• KT-39709 [FIR] False positive UNINITIALIZED_VARIABLE in presence of complex graph with jumps
• KT-39923 Result.Failure will get wrapped with Success when using with RxJava
• KT-40198 ‘$default’ methods in ‘kotlin/test/AssertionsKt’ generated as non-synthetic by JVM_IR
• KT-40200 IDE: Multiple top-level main functions in different files: broken highlighting, “No descriptor resolved for FUN”
• KT-40262 ACC_DEPRECATED flag not generated for property getter delegate in multifile class facade in JVM_IR
• KT-40282 Inline class wrapping Any gets double boxed
• KT-40464 JVM_IR does not generate LINENUMBER at closing brace of (suspend) lambda
• KT-40500 Warnings reporting by Java nullability annotations doesn't work for not top-level types
• KT-40926 IDE import actions do not add required import for convention invoke() extension call
• KT-40948 IllegalAccessError while initializing val property in EXACTLY_ONCE lambda that is passed to another function
• KT-40991 NI: UNRESOLVED_REFERENCE_WRONG_RECEIVER instead of FUNCTION_EXPECTED with convention invoke call
• KT-41163 Double wrapped value in Result class after map operation
• KT-41284 Spring CGLIB proxies break auto-generated data class componentN and copy methods when using JVM IR
• KT-41468 JVM IR: IllegalAccessError on access to abstract base member from another package, from anonymous object inside abstract class
• KT-41491 UNRESOLVED_REFERENCE_WRONG_RECEIVER instead of FUNCTION_EXPECTED when invoking non-functional value as a function
• KT-41493 JVM IR: names of classes for local delegated variables contain the variable name twice
• KT-41792 [FIR] Introduce & use ConeAttribute.UnsafeVariance
• KT-41793 [FIR] Make captured types accessible at the end of resolve
• KT-41809 JVM IR: name for internal $default method doesn't include module name
• KT-41810 JVM IR: Deprecated(HIDDEN) class is incorrectly generated as synthetic
• KT-41841 JVM IR: delegates for private functions with default arguments are generated in multifile classes
• KT-41857 Flaky ‘ConcurrentModificationException’ through kotlin.serialization.DescriptorSerializer
• KT-41903 JVM IR: do not generate LineNumberTable in auto-generated members of data classes
• KT-41911 JVM IR: nested big-arity function calls are not lowered
• KT-41957 JVM IR: step into suspend function goes to the first line of the file
• KT-41960 JVM IR: smart step into members implemented with delegation to interface doesn't work
• KT-41961 JVM IR: line numbers are not generated in JvmMultifileClass facade declarations
• KT-41962 JVM IR: intermittent -1 line numbers in the state machine cause double stepping in the debugger
• KT-42001 Cannot resolve symbol: AssertionError: Module <sdk 1.8> is not contained in his own dependencies
• KT-42002 JVM / IR: IllegalStateException: “No mapping for symbol: VAR IR_TEMPORARY_VARIABLE” caused by named arguments
• KT-42021 JVM / IR: “IndexOutOfBoundsException: Index 0 out of bounds for length 0” during IR lowering with suspend conversion
• KT-42033 JVM IR: accidental override in Map subclass with custom implementations of some members
• KT-42036 IR: “AssertionError: TypeAliasDescriptor expected: deserialized class Nothing” when referencing typealias with @UnsafeVariance
• KT-42043 JVM IR: Don't generate collection stubs when implementing methods with more specific return types
• KT-42044 Compiler error when lambda with contract surrounded with parentheses
• KT-42114 JVM_IR generates stub for ‘removeIf’ in abstract classes implementing ‘List’ and ‘Set’
• KT-42115 JVM_IR doesn't generate ‘next’ and ‘hasNext’ method in an abstract class implementing ‘ListIterator’
• KT-42116 FIR: Java accessor function should not exist in scope together with relevant property
• KT-42117 IR-based evaluator cannot handle Java static final fields
• KT-42118 FIR2IR: field-targeted annotation is placed on a property, not on a field
• KT-42130 FIR: type variable is observed after when condition analysis
• KT-42132 FIR2IR: companion function reference has no dispatch receiver
• KT-42137 JVM IR: AbstractMethodError on complex hierarchy where implementation comes from another supertype and has a more specific type
• KT-42186 JVM / IR: Infinite cycle in for expression when unsigned bytes are used in decreasing loop range
• KT-42251 JVM / IR: “IllegalStateException: Descriptor can be left only if it is last” when comparing the i-th element of the container of Int? and i with change
• KT-42253 JVM IR: NoSuchFieldError on local delegated property in inline function whose call site happens before declaration in the source
• KT-42281 JVM / IR: AnalyzerException when comparing Int and array that cast to Any in if condition
• KT-42340 FIR2IR: duplicating fake overrides
• KT-42344 IR-based evaluator doesn't support “annotation in annotation”
• KT-42346 FIR: double-vararg in IR while resolving collection literal as Java annotation argument
• KT-42348 FIR: false UNINITIALIZED_VARIABLE in local class
• KT-42350 FIR: false UNINITIALIZED_VARIABLE after initialization in try block
• KT-42351 FIR: false HIDDEN in enum entry member call
• KT-42354 JVM / IR: “AssertionError: Unexpected IR element found during code generation” with KProperty get invocation
• KT-42359 FIR2IR: cannot mangle type parameter
• KT-42373 FIR2IR: local object nested class has no parent if forward-referenced by nested class supertype
• KT-42384 FIR (BE): top-level field has no parent class in BE
• KT-42496 FIR resolve: synthetic property is written but has no setter
• KT-42517 FIR: exception in BE for recursive inline call
• KT-42530 “AssertionError: No type for resolved lambda argument” on attempting to assign a Pair to a couple of values in a scratch file
• KT-42601 [FIR] Inherited declaration clash for stdlib inheritors
• KT-42622 NI: IllegalStateException for if expression with method reference inside flow
• KT-42642 ISE: No getProgressionLastElement for progression type IntProgressionType
• KT-42650 JVM IR: extraneous nullability annotation on a generic function of a flexible type
• KT-42656 FIR2IR: unsupported callable reference for Java field
• KT-42725 Debugger steps into core library inline functions in chained calls
• KT-42758 JVM / IR: Deserialized object that overrides readResolve() is not reference equal to the singleton instance
• KT-42770 FIR: duplicating signatures in mangler (typealias for functional type)
• KT-42771 FIR: duplicating signature in mangler (data class with delegate)
• KT-42814 FIR: false UNINITIALIZED_VARIABLE in local function after if...else
• KT-42844 FIR: Property write in init block resolved to parameter write
• KT-42846 JVM_IR: NPE on function reference to @JvmStatic method in a different file
• KT-42933 JVM / IR: “AnalyzerException: Expected an object reference, but found I” with local delegate in inline class
• KT-43006 JVM/JVM_IR: do not generate no-arg constructor for constructor with default arguments if there are inline class types in the signature
• KT-43017 JVM / IR: AssertionError when callable reference passed into a function requiring a suspendable function
• KT-43051 JVM IR: extraneous methods overridding default (Java 8) collection methods in inline class that extends MutableList
• KT-43067 Inner class declaration inside inline class should be prohibited
• KT-43068 JVM IR: no generic signatures for explicitly written methods in a List subclass, whose signature coincides with MutableList methods
• KT-43132 JVM / IR: Method name ‘<get-...>’ in class ‘...$screenTexts$1$1’ cannot be represented in dex format.
• KT-43145 JVM IR: $default methods in multi-file facades are generated as non-synthetic final
• KT-43156 FIR: false UNINITIALIZED_VARIABLE after initialization in synchronized block
• KT-43196 JVM: extra non-static member is generated for extension property in inline class
• KT-43199 JVM IR: synthetic flag for deprecated-hidden is not generated for DeprecatedSinceKotlin and deprecation from override
• KT-43207 JVM IR: no collection stub for iterator is generated on extending AbstractCollection
• KT-43217 JVM_IR: Multiple FAKE_OVERRIDES for java methods using @NonNull Double and java double
• KT-43225 Confusing message of warning NULLABLE_TYPE_PARAMETER_AGAINST_NOT_NULL_TYPE_PARAMETER
• KT-43226 “Incompatible stack heights” with non-local return to outer lambda inside suspend lambda
• KT-43242 JVM / IR: “AnalyzerException: Expected I, but found R” caused by when inside object with @Nullable Integer subject
• KT-43249 Wrong code generated for suspend lambdas with inline class parameters
• KT-43286 JVM IR: IAE “Inline class types should have the same representation: Lkotlin/UInt; != I” on smart cast of unsigned type value with JVM target 1.8
• KT-43326 JVM_IR: No deprecated flag for getter of deprecated interface property copied to DefaultImpls
• KT-43327 JVM_IR: No deprecated or synthetic flag for accessors of deprecated-hidden property of unsigned type
• KT-43332 FIR: Smart casts lead to false-positive ambiguity
• KT-43370 JVM IR: No deprecated flag for getter of deprecated property copied via delegation by interface
• KT-43459 JVM_IR. Wrong signature for synthetic $annotations method for extension property on nullable primitive
• KT-43478 NI: “IndexOutOfBoundsException: Index: 3, Size: 3” caused by is check with raw type inside if condition with when inside
• KT-43519 JVM_IR. External functions generated differently in multi file facades
• KT-43524 JVM_IR. Missed deprecation flag on companion @JvmStatic property accessor
• KT-43525 Prohibit JvmOverloads on declarations with inline class types in parameters
• KT-43536 JVM IR: IllegalStateException is not caught by runCatching under Deferred.await() with kotlinx.coroutines
• KT-43562 JVM IR: incorrect mangling for Collection.size in unsigned arrays
• KT-43584 [FIR] Java annotations with named arguments aren't loaded correctly
• KT-43587 Invalid default parameter value in expect actual declaration on jvm
• KT-43630 “AssertionError: Number of arguments should not be less than number of parameters” during capturing intersection raw type with star projection
• KT-43698 NoSuchMethodError for inline class implementing interface with @JvmDefault methods, -Xjvm-default=enable
• KT-43741 Report error on inline class implementing ‘kotlin.Cloneable’
• KT-43845 org.jetbrains.kotlin.codegen.CompilationException: Back-end (JVM) Internal error: Failed to generate expression: KtBlockExpression
• KT-43956 NI: “Error type encountered – UninferredParameterTypeConstructor” on “try” and other constructs with code block as a value
• KT-44055 Left uninferred type parameter for callable references inside special calls
• KT-44113 Compiler frontend exception: Number of arguments should not be less than number of parameters, but: parameters=2, args=1
• KT-44145 No highlighting for not initialized base constructor and NoSuchMethodError in Android plugin

IDE

New Features

• KT-44075 Sealed interfaces: New Kotlin Class/File menu update

Fixes

• KT-29454 Light class with unexpected name when using obfuscated library
• KT-31553 Complete Statement: Wrong auto-insertion of closing curly brace for a code block
• KT-33466 IDE generates incorrect external override with body for overriding open external method
• KT-39458 Add CLI support for UL classes
• KT-40403 UAST: PsiMethod for invoked extension function/property misses @receiver: annotations
• KT-41406 Kotlin doesn't report annotations for type arguments (no way to add @Nls, @NonNls annotations to String collections in Kotlin)
• KT-41420 UAST does not return information about type annotations
• KT-42194 OOME: Java heap space from incremental compilation
• KT-42754 MPP: no smart cast for Common nullable property used in platform module
• KT-42821 MPP, IDE: Platform-specific errors are reported even when build doesn't target that platform
• KT-44116 Add language version 1.5 to the compiler configuration preferences
• KT-44523 IDE notification for trying new JVM backend
• KT-44543 Kotlin's LowMemoryWatcher leaks on Kotlin plugin unload

IDE. Android

• KT-42381 MPP: Bad IDEA dependencies: JVM module depending on built artifact instead of sources of module with Android Plugin applied

IDE. Completion

• KT-44016 Code completion: support for “sealed interface”
• KT-44250 Code completion does not work in when expression with sealed type argument

IDE. Gradle. Script

• KT-39105 AE “JvmBuiltins has not been initialized properly” after creating new Gradle/Kotlin-based project via old Project Wizard

IDE. Inspections and Intentions

New Features

• KT-22666 “Create enum constant” quick fix could be provided
• KT-24556 Add Remove quick fix for “Expression under ‘when’ is never equal to null”
• KT-34121 Report unused result of data class copy method
• KT-34533 INLINE_CLASS_CONSTRUCTOR_NOT_FINAL_READ_ONLY_PARAMETER: Add quickfix “Add val to parameter”
• KT-35215 Quickfix for CONST_VAL_NOT_TOP_LEVEL_OR_OBJECT to remove const modifier
• KT-40251 Intention action to evaluate compile time expression
• KT-44017 Sealed interfaces: Java side Inspection “implementation of Kotlin sealed interface is forbidden”
• KT-43941 Sealed interfaces: intention to extend class/interface
• KT-44043 Sealed interfaces: quickfix to move class/interface to proper location

Fixes

• KT-20420 Intention “Put arguments/parameters on separate lines” doesn't respect the “Place ‘)’ on new line” Kotlin code style setting
• KT-21799 Quickfix “Change function signature” for receiver type doesn't change it
• KT-22665 “Create object” quick fix produce wrong code for enum
• KT-23934 IntelliJ suggest “merge map to joinToString” even when such action is impossible due to suspending actions in map
• KT-30894 Wrong results of intention “Add names to call arguments” when backticked argument starts from digit
• KT-31523 ReplaceWith introduces additional argument name for lambda when named argument is used on call-site
• KT-31833 JavaMapForEachInspection should report for expression with implicit receiver
• KT-33096 Turn ‘MapGetWithNotNullAssertionOperator’ into an intention
• KT-33212 False positive “map.put() should be converted to assignment” inspection when class inherited from MutableMap has “set” method
• KT-34270 False negative “Join declaration and assignment” with constructor call
• KT-34859 False positive “Should be replaced with Kotlin function” inspection for Character.toString(int) function
• KT-34959 False positive “Redundant overriding method” with different implemented/overridden signatures
• KT-35051 False positive “Remove redundant backticks” if variable inside the string and isn't followed by space
• KT-35097 False positive “Call replaceable with binary operator” on explicit ‘equals’ call on a platform type value
• KT-35165 “Replace ‘if’ with elvis operator”: don't suggest if val initializer is a complex expression
• KT-35346 False positive ‘Make internal’ suggestion for function inside interface
• KT-35357 “Move lambda argument out of parentheses” does not preserve block comments
• KT-38349 Invalid suggestion to fold to elvis when having a var-variable
• KT-40704 False negative “Redundant semicolon” at start of line
• KT-40861 “Convert to secondary constructor” intention expected on class name
• KT-40879 False positive “Redundant ‘inner’ modifier” when calling another inner class with empty constructor
• KT-40985 “Remove explicit type arguments” is suggested when type has an annotation
• KT-41223 False positive “Redundant inner modifier” inspection ignores constructor arguments of object expressions
• KT-41246 False positive “Receiver parameter is never used” with anonymous function expression
• KT-41298 “Remove redundant ‘with’ call” intention works incorrectly with non-local returns and single-expression functions
• KT-41311 False positive “Redundant inner modifier” when deriving from a nested Java class
• KT-41499 “Convert receiver to parameter” produces code with incorrect order of generic type and function invocation in case of generic function with lambda as a parameter
• KT-41680 False positive “Redundant inner modifier” when deriving from class with non-empty constructor and value passed to it from enclosing class
• KT-42201 Add Opt-In action doesn't work if there is already OptIn annotation
• KT-42255 “Replace elvis expression with ‘if’ expression” intention shouldn't introduce unnecessary variable if ‘error’ expression is used

IDE. JS

• KT-43760 KJS: Debugging Kotlin code for Node.js runtime doesn't work

IDE. Misc

• KT-44018 Sealed interfaces: IDE side implementation for hierarchy provider

IDE. Multiplatform

• KT-40814 MISSING_DEPENDENCY_CLASS when consuming native-shared library in a source-set with fewer targets than library has

IDE. Run Configurations

• KT-34535 Unable to run common tests on Android via gutter icon in a multiplatform project

IDE. Scratch

• KT-25038 Scratch: Destructuring declaration produces an unresolved reference
• KT-43415 Kotlin scratch file could not be run and could lead to dead lock

IDE. Script

• KT-44117 IDE / Scripts: custom kotlin script definitions aren't loaded

JavaScript

Fixes

• KT-31072 Don't use non-reified arguments to specialize type operations in IR inliner
• KT-39964 Throwable incorrectly implements constructor for (null, cause) args in K/JS-IR
• KT-40090 KJS: IR. Invalid behaviour for optional parameters (redundant tail undefined parameters)
• KT-40686 KJS: Uncaught ReferenceError caused by external class as type inside eventListener in init block
• KT-40771 KJS / IR: “ReferenceError: Metadata is not defined” caused by default parameter value in inner class constructor
• KT-41032 KJS / IR: “AssertionError: Assertion failed” caused by class that is delegated to inherited interface
• KT-41076 KJS / IR: “AssertionError: Assertion failed” caused by overridden extensiion function in child class
• KT-41771 KJS / IR: IndexOutOfBoundsException “Index 0 out of bounds for length 0” caused by inline class with List in primary constructor and vararg in secondary
• KT-42025 KJS / IR: IrConstructorCallImpl: No such type argument slot: 0
• KT-42112 KJS: StackOverflowError on @JsExport in case of name clash with function with Enum parameter with star-projection
• KT-42262 KJS: break-statements without label are ignored in a when
• KT-42357 KotlinJS - external class constructor with vararg does not correctly handle spread operator.
• KT-42364 KJS: Properties of interface delegate are non-configurable
• KT-43212 JS IR: support init blocks inside inline classes
• KT-43222 KJS IR: prototype lazy initialization for top-level properties like in JVM
• KT-43313 KJS / IR: “Can't find name for declaration FUN” for secondary constructor
• KT-43901 Call to enum values() method from enum companion object leads to non-initialized enum instances

KMM Plugin

• KT-41677 Could not launch iOS project with custom display name
• KT-42463 Launch common tests for Android on local JVM via run gutter
• KT-43188 NoSuchMethodError in New Module Wizard of KMM Project

Libraries

• KT-41112 Docs: add more details about bit shift operations
• KT-41278 map.entries.contains can return false if the argument is not MutableEntry
• KT-41356 Incorrect documentation for rangeTo function
• KT-44456 Introduce locale-agnostic API for case conversions
• KT-44458 Introduce new Char-to-code and Char-to-digit conversions

Middle-end. IR

• KT-41765 [Native/IR] Could not resolveFakeOverride()
• KT-42054 Psi2ir: “RuntimeException: IrSimpleFunctionSymbolImpl is already bound” when using result of function with overload resolution by lambda return type

Native. C and ObjC Import

• KT-42412 [C-interop] Modality of generated property accessors is always FINAL

Native. ObjC Export

• KT-38530 Native: values() method of enum classes is not exposed to Objective-C/Swift
• KT-43599 K/N: Unbound symbols not allowed

Native. Platform libraries

• KT-43597 Support for Xcode 12.2 SDK

Native. Platforms

• KT-43276 Support watchos_x64 target

Native. Runtime

• KT-42822 Kotlin/Native Worker leaks ObjC/Swift autorelease references (and indirectly bridged K/N references) on Darwin targets

Native. Stdlib

• KT-42172 Kotlin/Native: StableRef.dispose race condition on Kotlin deinitRuntime
• KT-42428 Inconsistent behavior of map.entries on Kotlin.Native

Reflection

• KT-34024 “KotlinReflectionInternalError: Inconsistent number of parameters” with javaMethod on suspending functions with inline class in function signature or inside the function

Tools. CLI

• KT-43294 Support -no-stdlib option for the kotlin runner
• KT-43406 JVM: produce deterministic jar files if -d option value is a .jar file

Tools. CLI. Native

• KT-40670 Allow to override konan.properties via CLI

Tools. Compiler Plugins

• KT-41764 KJS /IR IllegalStateException: “Symbol for public kotlin/arrayOf is unbound” with serialization plugin
• KT-42976 kotlinx.serialization + JVM IR: NPE on annotation with @SerialInfo
• KT-43725 Prohibit inner and local classes in kotlin-noarg

Tools. Gradle

• KT-38692 KaptGenerateStubs Gradle task will not clean up outputs when sources are empty and not an incremental build
• KT-40140 kotlin-android plugin eagerly creates several Gradle tasks
• KT-41295 Kotlin Gradle Plugin 1.4.20 Configuration Caching bug due to friendPath provider
• KT-42058 Support moduleName option in Kotlin Gradle plugin for JVM
• KT-43054 Implementation of AbstractKotlinTarget#buildAdhocComponentsFromKotlinVariants breaks configuration caching
• KT-43489 Incremental compilation - unable to find history files causing full recompilation
• KT-43740 Gradle out-of-process runner fails with unclear diagnostics if build directory does not exist
• KT-43895 Fix cacheability warnings for the Kotlin plugins

Tools. Gradle. JS

• KT-42400 Kotlin/JS: Gradle DSL: customField() is rejected in Groovy build.gradle
• KT-42462 NPM dependency declaration with Groovy interpolated string
• KT-42954 Kotlin/JS: IDE import after changing kotlin.js.externals.output.format does not re-generate externals
• KT-43535 Common webpack configuration breaks on lambda serialization in some cases
• KT-43668 PackageJson task use file dependencies as is (files and directories), but only files necessary
• KT-43793 nodeArgs in NodeJsExec task
• KT-43842 KJS: Invalid output.library support for null value
• KT-44104 KJS / Gradle: An ability to pass jvm args to K2JSDce process

Tools. Gradle. Multiplatform

• KT-42269 Setup default dependsOn edges for Android source sets
• KT-42413 [MPP/gradle] withJava breaks build on 1.4.20-M1
• KT-43141 Gradle / Configuration cache: NPE from org.jetbrains.kotlin.gradle.tasks.KotlinCompileCommon.getKotlinOptions() on reusing configuration cache for task compileCommonMainKotlinMetadata
• KT-43329 Gradle / Configuration cache: IAE “Parameter specified as non-null is null: method KotlinMetadataTargetConfiguratorKt.isCompatibilityMetadataVariantEnabled, parameter $this$isCompatibilityMetadataVariantEnabled” on reusing configuration cache for task compileKotlinMetadata
• KT-44298 Kotlin 1.4.20+ MPP “root” module publication does not include the source JAR that used to be published in the -metadata modules

Tools. Gradle. Native

• KT-39564 Make kotlin-native Gradle tasks Cacheable
• KT-42485 Fail on cinterop: clang_indexTranslationUnit returned 1
• KT-42550 Adding subspec dependency with git location failed
• KT-42849 Gradle / Configuration cache: tasks nativeMetadataJar, runReleaseExecutableNative, runDebugExecutableNative are unsupported and fails on reusing configuration cache
• KT-42938 CocoaPods Gradle plugin: podBuildDependencies doesn't properly report xcodebuild failures
• KT-43151 Gradle / Configuration cache: UPAE “lateinit property binary has not been initialized” on reusing configuration cache for linkDebugExecutableNative, linkDebugTestNative, linkReleaseExecutableNative tasks
• KT-43516 Failed to resolve Kotin library [Multiple Multiplatform modules]

Tools. Incremental Compile

• KT-42937 another compilation fail (problem with compilation caches?)

Tools. JPS

• KT-39536 JPS compilation fails with IOException “storage is already closed”

Tools. Parcelize

• KT-41553 JVM IR, Parcelize: IrStarProjectionImpl cannot be cast to class IrTypeProjection

Tools. Scripts

• KT-43534 Allow running “main.kts” script that does not end in a “main.kts” filename (would allow kotlin scripting on GitHub Actions)

Tools. kapt

• KT-34340 Incremental annotation processor recompile all files (only if KAPT enabled).
• KT-36667 Kapt: Add a flag to strip kotlin.Metadata() annotations from stubs
• KT-40493 KAPT does not support aggregating annotations processors in incremental mode
• KT-40882 Kapt stub generation is non-deterministic for incremental compilation
• KT-41788 NullPointerException: Random crashes of build using gradle and kapt because of not calling Processor.init()
• KT-42182 KAPT: Does not consider generated sources for incremental compilation.

1.4.20

Android

• KT-42121 Deprecate Kotlin Android Extensions compiler plugin
• KT-42267 Platform declaration clash error in IDE when using kotlinx.android.parcel.Parcelize
• KT-42406 Long or infinite code analysis on simple files modification

Backend. Native

• KT-27534 Bridges to Nothing-returning methods have incorrect signature
• KT-30284 Native: Nothing? type for expression override and crash
• KT-36430 Optimize when with in range cases
• KT-38787 Missing optimization for “in range” check
• KT-39100 Make Native behaviour of property initialization consistent with JVM
• KT-39798 Override equals/hashCode in functional interface wrappers on Native
• KT-39800 equals/hashCode on adapted function references on Native
• KT-41394 Compilation failed: Backend Internal error: Exception during IR lowering
• KT-41907 Framework test segfaults on GC on watchos_x86 compiled with -opt

Compiler

New Features

• KT-21147 JEP 280: Indify String Concatenation (StringConcatFactory)
• KT-34178 Scripts should be able to access imports objects
• KT-35549 Support kotlin-android-extensions in JVM IR backend (for use with Jetpack Compose projects)
• KT-31567 Support special semantics for underscore-named catch block parameters

Performance Improvements

• KT-20571 Coroutines: Reduce number of local variables stored at suspension point
• KT-28016 Coroutine state-machines spill/unspill shall be optimized using data-flow analysis
• KT-33394 UI freezes triggered by QualifiedExpressionResolver.resolveToPackageOrClassPrefix
• KT-36814 Support optimized delegated properties in JVM_IR
• KT-36829 Optimize ‘in’ expressions (operator fun contains) in JVM_IR
• KT-41741 NI: “AssertionError: Empty intersection for types” with generic Java collection
• KT-42195 NI: prohibitively long compilation time for values of nested data structures with type inference
• KT-42221 Native compiler never finishes frontend phase after migrating to Kotlin 1.4.10

Fixes

• KT-11713 Refine visibility check for synthetic property with protected setter
• KT-16222 Coroutine should be clearing any internal state as soon as possible to avoid memory leaks
• KT-25519 Extra inline marks inside suspending function callable reference bytecode
• KT-33226 Object INSTANCE field not annotated with NotNull in generated bytecode
• KT-35495 FIR: forbid non-Java synthetic properties
• KT-35651 Kotlin stdlib has greater resolution priority than jars added via @file:DependsOn annotation
• KT-35716 Using @JvmOverloads in @JvmStatic functions in interface companion objects causes a ClassFormatError
• KT-35730 FIR: consider creating fake overrides for objects
• KT-36951 IllegalStateException: Expected some types: Throwing exception when there is a type parameter upper bound for itself
• KT-37321 [FIR] Support java array in type argument
• KT-37431 [FIR] Support Builder Inference
• KT-38272 FIR2IR: use lazy IR symbols for externals & fake overrides
• KT-38333 FIR: CCE on red code with assignment used as expression
• KT-38334 FIR: CCE when resolving try-as-expression
• KT-38336 FIR: NPE with corrupted numeric constant literal
• KT-38397 FIR: Exception while resolving contract definition
• KT-38444 [FIR] Invoke extension lambda with safe call
• KT-38470 FIR: ConeDefinitelyNotNullType in signature
• KT-38471 FIR: ConeIntersectionType in signature
• KT-38925 Internal error: wrong bytecode generated. (AssertionError: int type expected, but null was found in basic frames)
• KT-38989 FIR: Refine sealed classes exhaustiveness in case of sealed subclass
• KT-38992 FIR: Refine type resolution for inner classes
• KT-39000 FIR: Support smartcast after reference equality check
• KT-39005 FIR: Resolve plusAssign in a dependent context
• KT-39008 FIR: Investigate strange effect of type alias and not-nullable bound on inference
• KT-39012 FIR: Inference doesn't get through elvis to lambda parameter
• KT-39028 FIR: Strange resolution to synthetic property with implicit extension receiver while there's an explicit receiver
• KT-39032 FIR: Ambiguity in member scope of a type parameter with multiple bounds
• KT-39033 FIR: Ambiguity when calling generic overridden property
• KT-39034 FIR: Support nested extension function types
• KT-39040 FIR: Deserialize annotations from compiled Kotlin binaries
• KT-39043 FIR: Bare types incorrectly work with type aliases
• KT-39044 FIR: Add fillInStackTrace to member scope of kotlin.Throwable
• KT-39046 FIR: Implicit types in lambdas left when call argument is a type cast
• KT-39048 FIR: Inference fails with integer literal used as Comparable
• KT-39050 FIR: Type resolver doesn't see nested classes from super class of a local class
• KT-39070 FIR: Ambiguity on super calls to hashCode/equals when having super interface and class
• KT-39072 FIR: Subtyping check doesn't affect nullability of safe-call receiver
• KT-39076 FIR: Synthetic property is not a var because of @Nullable annotation on parameter
• KT-39080 FIR: Smart casts remain incorrect if lambda is present in when branch
• KT-39374 Wrong bytecode generated for suspend function call with EXACTLY_ONCE lambda capturing a variable initialized in when-subject
• KT-39621 [FIR] Support when exhaustiveness checker for java enums
• KT-40135 JVM IR does not generate restricted suspend lambdas
• KT-40382 Missing proper jvmSignature for synthesized equals/hashCode/toString in inline classes
• KT-40605 JVM IR: IndexOutOfBoundsException caused by inner class passed to generic outer class method with Nothing type argument
• KT-40664 JVM: No bounds check in optimization of ULong in UInt..UInt
• KT-40665 JVM: No resolved function check when optimizing in/contains with mismatched bound types
• KT-41014 FIR2IR: when/where/how to determine the presence of a backing field for a property
• KT-41018 FIR2IR: sort members during de/serialization
• KT-41144 False positive “Redundant spread operator” in when statement and generic vararg argument
• KT-41218 HMPP: arrayList declarations are visible both from stdlib-common and stdlib-jvm and lead to false-positive resolution ambiguity in IDE
• KT-41374 JVM / IR: NoSuchMethodError in Android project compiler caused by combination of inline classes and coroutines
• KT-41388 NI: Backend Internal error: Exception during IR lowering
• KT-41429 Inline class returned from suspend function should be boxed on resume path
• KT-41465 JVM / IR: “AssertionError: inconsistent parent function for CLASS LAMBDA_IMPL CLASS name” caused by inline method call into multiple constructors
• KT-41484 JVM IR: support -Xemit-jvm-type-annotations
• KT-41668 JVM IR: incorrect enclosing constructor for lambdas in initializers of inner classes
• KT-41669 JVM IR: incorrect hashCode intrinsic is used in JVM target 1.8 for generic type substituted with primitive
• KT-41693 NI: Type inference in nested expression incorrectly assumes non-nullable return type of Java function, causing NullPointerException
• KT-41729 NI: UnsupportedOperationException with invalid callable reference
• KT-41761 JVM IR: CCE from backend on generating typeOf for non-reified type parameter with star projection in upper bound
• KT-41789 Missing DebugMetadata in inlined suspend lambda
• KT-41913 NI: Kotlin 1.4 type inference breaks valid code
• KT-41934 NI: a type variable for lambda parameter has been inferred to nullable type instead of not null one
• KT-42005 JVM / IR: “NullPointerException: Parameter specified as non-null is null” when toString is called on inline class with not primitive property
• KT-42450 NI: “IllegalStateException: Error type encountered: NonFixed:” with coroutines
• KT-42523 Missed DefaultImpls for interface in -jvm-default=all mode on inheriting it from interface compiled in old scheme
• KT-42524 Wrong specialization diagnostic is reported on inheriting from java interface with default with -Xjvm-default=all-compatibility
• KT-42546 HMPP: incorrect subtyping of nullable types & overload resolution ambiguity on using and expect-function declaration with nullable expect in a signature
• KT-17691 Wrong argument order in resolved call with varargs
• KT-25114 Prohibit @JvmStatic on functions in private companions
• KT-33917 Prohibit to expose anonymous types from private inline functions
• KT-35870 Forbid secondary enum class constructors which do not delegate to the primary constructor
• KT-39098 NI: parameter of anonymous function can be inferred to Any? if another parameter's type is specified
• KT-41176 NI with Gson: “ClassCastException: java.util.ArrayList cannot be cast to java.lang.Void”
• KT-41194 ClassCastException on returning Result.failure from lambda within suspend function
• KT-42438 NI: ClassCastException: cannot be cast to java.lang.Void caused by when statement in run function
• KT-42699 False positive NON_JVM_DEFAULT_OVERRIDES_JAVA_DEFAULT diagnostic in new jvm-default modes
• KT-42706 Kotlin 1.4 infers generic is Nothing instead of actual Foo class (Android project)

Docs & Examples

• KT-42318 No documentation for kotlin.js.js

IDE

New Features

• KT-20775 More kotlin kinds in new kotlin file/class menu
• KT-31331 Improve: Optimize Import should remove unused unresolved imports
• KT-31500 Smart enter: support get() clause
• KT-39231 Injection: Add receiver of kotlin.text.toPattern to standard Kotlin injections
• KT-39844 Add specific highlight for Enum class

Performance Improvements

• KT-39353 Implement EnterBetweenBracesNoCommitDelegate
• KT-39720 A lot of freezes in Kotlin project
• KT-41634 Deadlock in org.jetbrains.kotlin.idea.framework.LibraryEffectiveKindProviderImpl.getEffectiveKind
• KT-41936 Impossible to work with Kotlin 1.4 in 202 idea, idea eats all cpu

Fixes

• KT-10790 “Move statement up” for @file-targeted annotation moves package declaration to bottom of file
• KT-15262 “Generate toString()” is ignoring property if it has a getter
• KT-24352 Method separators: displayed between properties, not displayed between companion object and function
• KT-29364 “Extend selection” can't select lambda body with parameters
• KT-32403 Clickable links in annotation parameters (like in TODOs)
• KT-32409 Organizing imports should not remove imports while there are unresolved symbols
• KT-34566 Too small indent after line break for multi line strings
• KT-34587 “Move statement down” doesn't work for statement in constructor with end-of-line comment
• KT-34705 “Move statement down” for penultimate statement with end-of-line comment in constructor leads to moving comma to the end of comment
• KT-34707 “Move statement up” for last statement with end-of-line comment in constructor leads to moving comma to the end of comment
• KT-35424 FIR IDE: Kotlin project does not see stdlib
• KT-35732 URLs in String literals are not clickable
• KT-35859 Language injection doesn't work with named arguments in different position
• KT-37210 UAST: KtLightClassForSourceDeclaration.isInheritor sometimes returns the wrong result
• KT-37219 File level OptIn annotation is not recognized by the IDE
• KT-38959 IDE: False negative EXPLICIT_DELEGATION_CALL_REQUIRED, “IllegalArgumentException: Range must be inside element being annotated”
• KT-39398 Wrong import of unrelated object member is suggested for receiver
• KT-39457 Separate decompiled declarations Light implementation from LightClasses infrastructure
• KT-39899 KotlinOptimizeImportsRefactoringHelper: ISE: Attempt to modify PSI for non-committed Document
• KT-40578 UAST: write accesses to Kotlin properties should resolve to setter
• KT-41290 KotlinClassViaConstructorUSimpleReferenceExpression resolves to PsiMethod instead of PsiClass
• KT-42029 HMPP, IDE: NPE from FacetSerializationKt.getFacetPlatformByConfigurationElement on project opening
• KT-43202 On 1.4.20-RC version AS ask for xml compatibility update for EAP version of plugin
• KT-42883 No highlighting for elements marked as @Deprecated in stdlib

IDE. Android

• KT-42406 Long or infinite code analysis on simple files modification
• KT-42061 Highlighting is broken in Android activity
• KT-41930 Android Studio 4.2 cannot start after updating to 1.4.20 plugin with error: Missing essential plugin: org.jetbrains.android

IDE. Completion

• KT-26235 Kotlin methods/fields don't have icons in Java completion

IDE. Debugger

• KT-37486 Kotlin plugin keeps reference to stream debugger support classes after stream debugger plugin is disabled
• KT-38659 Evaluate Expression: toString() on variable returns error when breakpoint is in commonTest sourceset
• KT-39309 Debugger: Prolonged “Collecting data” for variables when breakpoint is inside respondHtml
• KT-39435 “Collecting data...” in debugger variables view never finishes
• KT-39717 Debugger shows “Collecting data...” forever for instances of some class
• KT-40386 Memory leak detected: ‘org.jetbrains.kotlin.idea.debugger.coroutine.view.XCoroutineView’
• KT-40635 Coroutines Debugger: make IDE plugin accept coroutines 1.3.8-rc* versions as well
• KT-41505 Coroutines Debugger: “Access is allowed from event dispatch thread with IW lock only.”

IDE. Decompiler, Indexing, Stubs

• KT-28732 Stub file element types should be registered early enough
• KT-41346 IDE: “AssertionError: Stub type mismatch: USER_TYPE!=REFERENCE_EXPRESSION” with CollapsedDumpParser class from IDEA SDK
• KT-41859 File analysis never ending with kotlinx.cli (AssertionError: Stub type mismatch: TYPEALIAS!=CLASS)
• KT-41640 “Project roots have changed” happened during indexing because of org.jetbrains.kotlin.idea.core.script.ucache.ScriptClassRootsUpdater$notifyRootsChanged increases overall indexing time.
• KT-41646 “AssertionError: ContentElementType: FILE”; Code analysis never finishes on some files from my project

IDE. Gradle Integration

• KT-34271 Support pureKotlinSourceFolders for MPP projects
• KT-37106 Gradle + IDE integration: on creating source roots from Project tree IDEA creates incorrect settings
• KT-38830 addTransitiveDependenciesOnImplementedModules performance is slowing down Android Studio Gradle Sync
• KT-41703 Kotlin plugin not functional: PluginException: While loading class org.jetbrains.kotlin.idea.core.script.KotlinScriptDependenciesClassFinder

IDE. Gradle. Script

• KT-35092 “Unable to get Gradle home directory” popup and no build.gradle.kts highlighting right after creating a new project
• KT-37590 Wrong notification for precompiled build script
• KT-39523 Go to Declaration navigates to decompiled classfile instead of sources in case of jumping to Gradle plugin sources in buildSrc
• KT-39542 EA-218043: java.util.NoSuchElementException: No element of given type found (GradleBuildRootsManager)
• KT-39790 List of standalone script should be saved between IDE restarts
• KT-39910 build.gradle.kts isn't highlighted after import
• KT-39916 init.gradle.kts isn't highlighted
• KT-40243 gradle.kts: standalone script under build root isn't highlighted as standalone
• KT-41141 Gradle Kotlin DSL: “cannot access ‘java.lang.Comparable’. Check your module classpath” with empty JDK in Project structure
• KT-41281 Multiple Script Definitions warning shown in git project having multiple Gradle projects

IDE. Hints

• KT-32368 Rework Inline hints settings so that they look appropriate with the new UI in 2019.3
• KT-38027 Support Code Vision feature in Kotlin
• KT-42014 ClassNotFoundException in Android Studio 4.2 after installing 1.4.20 plugin

IDE. Hints. Parameter Info

• KT-24172 Parameter info marks signature as inapplicable when using argument labels
• KT-41617 Parameter Info shows nothing inside already present type arguments of supertype
• KT-41645 Add support for mixed named arguments to parameter info popup

IDE. Inspections and Intentions

New Features

• KT-14578 Suggest “Convert lambda to reference” intention for generic extension function
• KT-19321 Warn if method with nullable return type always returns non-null
• KT-20718 Add a quick fix for “this class has no constructor” error on ‘expect’ annotation classes
• KT-21223 Add inspection for incomplete destructuring
• KT-22420 Intention to replace a = b with b.also { a = it }
• KT-39930 Add inspection for nullable Boolean in if condition
• KT-40016 Replace ‘a.toLowerCase() == b.toLowerCase()’ with ‘a.equals(b, ignoreCase = true)’ inspection
• KT-40283 Inspection which replaces also/apply with nested forEach to onEach
• KT-40769 Add intention to replace isBlank/isNotBlank method negation

Fixes

• KT-12222 Intention ‘Convert to block body’ should take nullability of overriden method into account when expression is of platform type
• KT-14395 Lambda to Reference doesn't work for generic types
• KT-15846 ‘Change lambda expression return type’ quick fix does nothing
• KT-15944 IDEA doesn't suggest to replace deprecated get set operator functions when it used as operator
• KT-17222 “Convert reference to lambda” creates red code for method with default argument values
• KT-18125 “Wrap with let {...}” intention not available in all cases
• KT-20438 Naming convention inspections: factory functions that are named like classes are flagged
• KT-24138 Incorrect behavior in “convert reference to lambda” with new inference enabled, on function reference with default arguments
• KT-29844 “Create class from usage” should mark constructor of created class as internal if its parameters have internal visibility
• KT-30928 “Show hints for suspend calls” is too easy to enable and hard to disable
• KT-31749 “Surround with null check” produces incorrect check for ‘in’ expression
• KT-32963 Don't suggest java directory of a JVM source set in multiplatform project as a target for Create actual quick fix
• KT-33211 Quickfix “add parameter” for method references should infer functional type instead of KFunction
• KT-33258 “Merge ‘if’s” intention drops comment before nested if
• KT-34572 Convert to block body action improperly works with suppress annotations
• KT-35128 Intention Convert member to extension hides property delegate text with single line comment
• KT-35214 Intention Put parameters on one line: don't suggest if parameters has end-of-line comments
• KT-35320 False positive “Replace explicit parameter ‘x’ with ‘it’” in ‘when’ expression which returns lambda
• KT-35525 False positive intention for ‘run’: “Convert to ‘let’” when invoked without receiver
• KT-35526 Intention “Eliminate argument of ‘when’” is broken for ‘when’ expression without ‘else’ branch
• KT-35805 FoldInitializerAndIfToElvis: should not add new line for multiline initializer
• KT-36051 IfThenToSafeAccessInspection: do not report if condition is SENSELESS_COMPARISON
• KT-37748 “Convert anonymous function to lambda expression” intention does not add necessary lambda type parameter
• KT-37841 IllegalStateException after “add non-null asserted call” on nullable function reference
• KT-38139 False negative “Add suspend modifier” quickfix when suspend function is called in inline lambda
• KT-38267 False positive “Call on collection type may be reduced” with Java platform types: suggested to reduce ‘mapNotNull’ call to ‘map’
• KT-38282 False positive “Remove redundant spread operator” inspection with array as class property or fun argument
• KT-38915 “Remove explicit type specification” intention should be disabled in explicit API mode
• KT-38981 “Specify return type explicitly” inspection is not reported for declaration annotated with @PublishedApi in Explicit Api mode
• KT-39026 ‘Specify return type explicitly’ intention duplicates compiler warning in Explicit api mode
• KT-39200 False positive “Redundant qualifier name” with same-named member object and companion property
• KT-39263 False positive “Variable should be inlined” for override value in initialized object
• KT-39311 Batch quick fix name for “Change file's package” is truncated
• KT-39393 “Convert anonymous function to lambda expression” intention does not add necessary lambda type parameter for outer function
• KT-39454 False positive “Unused symbol” with private anonymous object property
• KT-39467 False negative “Move variable declaration into when” if a variable declaration is placed on a new line
• KT-39490 ‘Wrap with ?.let’ quickfix put the receiver in let lambda
• KT-39552 Merge ‘if’s intention drops comment after nested if
• KT-39604 “Package directive doesn't match file location” quick fix does not insert a space between keyword package and the package name
• KT-39772 “Redundant ‘Unit’” should support lambdas
• KT-40215 “Create abstract function” quick fix suggested even though surrounding class is non-abstract
• KT-40448 “Convert call chain into sequence”: support functions added in Kotlin 1.4
• KT-40558 False positive “Move to class body” intention on data class constructor property
• KT-41338 False positive “Redundant ‘asSequence’ call” when Map.Entry properties are used.
• KT-41615 “Unused equals expression” inspection: highlight whole expression with yellow background
• KT-43037 Disable “Incomplete destructuring declaration” in 1.4.20

IDE. J2K

• KT-20421 J2K: SUPERTYPE_NOT_INITIALIZED for object extending base class
• KT-37298 J2K: implicit widening conversion for whole argument expression is transformed to cast on subexpression
• KT-38879 J2K loses class annotations when converting class to object
• KT-39149 J2K fails with augmented assignment operators when multiplying int by a non-int
• KT-40359 J2K: Conversion of invalid octal numbers throws NumberFormatException
• KT-40363 J2K: Converting HEX integer literal in for-loop throws NumberFormatException

IDE. JS

• KT-39319 KJS: Support debugging through new Intellij 202 API
• KT-41328 KJS / Gradle: explicitApi mode doesn't work

IDE. KDoc

• KT-17926 IDE should show documentation for a class if the constructor has no docs.
• KT-19069 KDoc: show default argument values
• KT-37132 Redundant @NotNull annotation in a Quick Documentation pop-up

IDE. Misc

• KT-39327 Get rid of usages of internal classes ModuleOrderEntryImpl and LibraryImpl
• KT-40455 Improve support for EditorConfig

IDE. Navigation

• KT-24616 Find usages fails to find setter usage
• KT-38762 “Cannot access ‘java.io.Serializable’ which is a supertype of ‘kotlin.Int’” brokes navigation to constructor parameter declaration
• KT-39558 Call Hierarchy shows references from KDoc
• KT-40788 “Find usages” on Java getter overridden in Kotlin doesn't find synthetic property usage when it is called without base declaration
• KT-40960 Unable to find usages in java of Kotlin constructor in library when sources is attached.

IDE. Project View

• KT-37528 ‘Add Kotlin File/Class’ suggests file before class

IDE. Refactorings

• KT-19744 “Change Signature” is not available on constructor keyword in primary constructor
• KT-22170 “Change Signature” ignores Java usages of methods marked with @JvmStatic
• KT-37517 Invalid qualified name on copy-paste in build.gradle.kts

IDE. Run Configurations

• KT-24463 MPP, Intellij runner: Run does not add resource directory to classpath
• KT-36370 Hide run gutter icons for not yet implemented targets in multiplatform projects
• KT-39788 MPP, Gradle runner: Run does not add resource directory to classpath on project reopen without Gradle sync

IDE. Scratch

• KT-40557 IDE / Scratch: .kt files are treated as Kotlin scratches, opening fails

IDE. Script

• KT-35825 Custom kotlin scripts have no project import suggestions in sub modules.
• KT-39796 Performance of KotlinScriptDependenciesClassFinder
• KT-41622 IDE: Kotlin scripting support can't find context class from same project
• KT-41905 IDE / Script: FilePathPattern parameter in @KotlinScript annotation is not reflected correctly in Pattern / Extension
• KT-42206 Cannot load script definitions using org.jetbrains.kotlin.jsr223.ScriptDefinitionForExtensionAndIdeConsoleRootsSource

IDE. Tests Support

• KT-28854 Run/Debug configurations: “Redirect input from” option is not available for Kotlin apps
• KT-36909 IDE attempts to run non-JVM tests launched from context menu as JVM ones
• KT-37799 Don't show a target choice in context menu for a test launched on specific platform

IDE. Wizards

• KT-37965 New Project wizard 1.4+: adding JUnit5 test library add dependency to runner
• KT-40527 Node.JS application template in New Project Wizard
• KT-40874 Open new project wizard help page in browser when clicking help button in new project wizard
• KT-41417 Add react template to new project wizard
• KT-41418 Wizard: Support KJS compiler choice
• KT-41958 New project wizard: Backend/Console applications template with Groovy DSL missing compileTestKotlin block
• KT-42372 Rrename test classes in wizard template to avoid name clashing

JavaScript

• KT-38136 JS IR BE: add an ability to generate separate js files for each module and maybe each library
• KT-38868 [MPP / JS / IR] IllegalStateException: “Serializable class must have single primary constructor” for expect class without primary constructor with @Serializable annotation
• KT-39088 [ KJS / IR ] IllegalStateException: Concrete fake override IrBasedFunctionHandle
• KT-39367 KJS: .d.ts generation not working for objects
• KT-39378 KJS / IR: “IllegalStateException: Operation is unsupported” with binaries.executable() and external function inside for loop with Iterator as return type
• KT-41275 KJS / IR: “IllegalStateException: Can't find name for declaration FUN” caused by default value in constructor parameter
• KT-41627 KJS / IR / Serialization: IllegalStateException: Serializable class must have single primary constructor
• KT-37829 Kotlin JS IR: “Properties without fields are not supported” for companion objects
• KT-39740 KJS / IR: Can't use Serializable and JsExport annotations at the same time

KMM Plugin

• KT-41522 KMM: exceptions for Mobile Multiplatform plugin are suggested to report to Google, not JetBrains
• KT-42065 [KMM plugin] iOS apps fail to launch on iOS simulator with Xcode 12

Libraries

• KT-41799 String.replace performance improvements
• KT-43306 Deprecate createTempFile and createTempDir functions in kotlin.io
• KT-19192 Provide file system extensions/APIs based on java.nio.file.Path
• KT-41837 Remove @ExperimentalStdlibApi from CancellationException

Middle-end. IR

• KT-40193 IR: pluginContext.referenceClass() is not resolving typealias
• KT-41181 Kotlin/Native 1.4.0 compiler fails on data class with >120 fields

Native. C and ObjC Import

• KT-41250 [C-interop] Stubs for C functions without parameter names should have non-stable names
• KT-41639 Use LazyIR for enums and structs from cached libraries
• KT-41655 Native: “type cnames.structs.S of return value is not supported here: doesn't correspond to any C type” when accessing forward-declared-struct-typed C global variable

Native. ObjC Export

• KT-38641 Kotlin-Multiplatform: Objective-C description method name collision in Swift
• KT-39206 New line characters in @Deprecated annotation cause syntax error in Kotlin/native exported header

Native. Platform libraries

• KT-42191 Support for Xcode 12

Native. Runtime. Memory

• KT-42275 “Memory.cpp:1605: runtime assert: Recursive GC is disallowed” sometimes when using Kotlin from Swift deinit

Native. Stdlib

• KT-39145 MutableData append method

Tools. Android Extensions

• KT-42342 Build fails with java.lang.RuntimeException: Duplicate class found in modules on checkDebug(Release)DuplicateClasses task when both kotlin-parcelize and kotlin-android-extensions plugins are applied

Tools. CLI

• KT-35111 Extend CLI compilers help with link to online docs
• KT-41916 Add JVM target bytecode version 15

Tools. Commonizer

• KT-41220 [Commonizer] Short-circuit type aliases
• KT-41247 [Commonizer] Missed supertypes in commonized class
• KT-41643 Commonizer exception for targets [ios_x64], [macos_x64]
• KT-42574 HMPP: unresolved platform.* imports in nativeMain source set

Tools. Compiler Plugins

• KT-36329 Provide diagnostic in kotlinx.serialization when custom serializer mismatches property type
• KT-40030 Move the Parcelize functionality out of the Android Extensions plugin

Tools. Gradle

• KT-33908 Make Kotlin Gradle plugin compatible with the Gradle configuration cache
• KT-35341 KotlinCompile: Symlinked friend paths are no longer supported

Tools. Gradle. JS

New Features

• KT-35330 Allow to customise generated package.json
• KT-39825 Provide single point of Webpack configuration in Gradle script
• KT-41054 Support Yarn resolutions
• KT-41340 Add flag to suppress kotlin2js deprecation message
• KT-41566 Kotlin/JS: Support JavaScript Library distribution
• KT-42222 KJS / Gradle: “Cannot find package@version in yarn.lock” when npm dependencies of one package but with different version are used in project
• KT-42339 Support dukat binaries generation

Fixes

• KT-39515 package.json is regenerated without a visible reason
• KT-39838 Kotlin/JS Gradle tooling: NPM dependencies of different kinds with different versions of the same package fail with “Cannot find package@version in yarn.lock”
• KT-39995 Collect statistic about generateExternals feature
• KT-40087 Kotlin/JS, IR backend: browserRun: update in continuous mode fails: “ENOENT: no such file or directory” referring output .js
• KT-40159 Implement workaround / fix for webpack's “window is not defined”
• KT-40178 Browser run task prints output in TeamCity format
• KT-40201 Kotlin/JS: Gradle: public package.json has empty devDependencies {}
• KT-40202 Kotlin/JS: Gradle: NPM version range operators are written into package.json as escape sequences
• KT-40342 [Gradle, JS, Maven] “Cannot find module” generating fake NPM module from Maven dependendency
• KT-40462 Collect statistic about usages of kotlin.js.generate.executable.default option
• KT-40753 Type script definition file is not referenced as types in the package.json
• KT-40812 Node.JS run working directory
• KT-40865 KJS / Gradle: Registering a task with a type that directly extends AbstractTask has been deprecated
• KT-40986 KJS / Gradle: BuildOperationQueueFailure when two different versions of js library are used as dependencies
• KT-41125 Bump NPM versions in 1.4.20
• KT-41286 KJS / Gradle: args order in runTask is changed in 1.4.0
• KT-41475 KJS / Gradle: debug mode doesn't support custom launchers in karma config
• KT-41662 Kotlin/JS: with CSS support mode == “extract” browser test fails even without CSS usage: “Error in config file!”
• KT-42494 KJS / Gradle: “Configuration cache state could not be cached” caused by Gradle configuration cache

Tools. Gradle. Native

• KT-39764 Assertions are disabled when running K/N compiler in Gradle process
• KT-39999 Cocoapods plugin's dummy header cannot be compiled
• KT-40999 CocoaPods Gradle plugin: Support custom cinterop options when declaring a pod dependency.
• KT-41367 CocoaPods Gradle plugin: support git repository dependency
• KT-41844 Kotlin 1.4.10 gradle configuration error with cocoapods using multiple multiplatform modules
• KT-42531 Gradle task “podGenIos” fails if a Pod with a static library is added.

Tools. Incremental Compile

• KT-37446 Incremental analysis for Java sources fails when run on JDK 11

Tools. Parcelize

• KT-39981 Android parcel ‘java.lang.VerifyError: Bad return type’
• KT-42267 Platform declaration clash error in IDE when using kotlinx.android.parcel.Parcelize
• KT-42958 False positive IDE error on classes with kotlinx.parcelize.Parcelize on project initial import
• KT-43290 Typo in error message for ErrorsParcelize.DEPRECATED_ANNOTATION - kotlin.parcelize instead of kotlinx.parcelize
• KT-43291 Diagnostic deprecation messages should not be shown in case kotlin-android-extensions plugin is applied

Tools. Scripts

• KT-37987 Kotlin script: hyphen arguments not forwarded to script
• KT-38404 Scripting API: Provide Location of Annotation Usage
• KT-39502 Scripting: reverse order of Severity enum so that ERROR > INFO
• KT-42335 No “caused by” info about an exception that thrown in Kotlin Script

Tools. kapt

• KT-25960 Interfaces annotated with JvmDefault has wrong modifiers during annotation processing
• KT-37732 Kapt task is broken after update to 1.3.70/1.3.71
• KT-42915 Kapt generates invalid stubs for static methods in interfaces in Kotlin 1.4.20-M2

1.4.10

Compiler

Performance Improvements

• KT-41149 NI: Upgraded project from 1.3.72 to 1.4.0 hangs during build
• KT-41335 Kotlin Out of Memory When evaluating expression
• KT-41400 NI: Huge performance regression for kotlin compiler from 1.3.72 to 1.4.0 due to using list of dozen lambdas in a call

Fixes

• KT-41005 Coercion to Unit doesn't take into account nullability of a return type for lambda
• KT-41043 NI: StackOverflowError through PostponedArgumentInputTypesResolver.getAllDeeplyRelatedTypeVariables
• KT-41135 Type Inference Regression For Property Delegate With Receiver Type
• KT-41140 Unresolved reference to parameter of a catch block from lambda expression on 1.4.0
• KT-41150 IllegalStateException: Couldn't obtain compiled function body for public final inline fun
• KT-41164 NI: “IllegalStateException: Error type encountered” with callbackFlow builder inside condition
• KT-41202 Type inference fails in 1.4.0
• KT-41218 HMPP: arrayList declarations are visible both from stdlib-common and stdlib-jvm and lead to false-positive resolution ambiguity in IDE
• KT-41308 1.4.0 Type inference regression in suspend blocks with elvis operator expressions
• KT-41357 ClassCastException for unstable smart cast on a property call receiver
• KT-41386 NI: Type mismatch with generic type parameters
• KT-41426 Operator compareTo is not called with nullable type
• KT-41430 Broken choosing overload by lambda return type inside builder inference
• KT-41470 Wrong nullability assertion is generated when using the BuilderInference annotation
• KT-41482 Add a fallback compiler flag to disable the unified null checks behavior

IDE

• KT-41325 SOE in IDEKotlinAsJavaSupport
• KT-41390 Typo: equals & hashCode are written with the first uppercase letter

IDE. Code Style, Formatting

• KT-41314 Formatter: Frequent freezes when reformatting code (TrailingCommaPostFormatProcessor)

IDE. Debugger

• KT-40417 Coroutines Debugger: “No coroutine information found” in case of main() entry-point without explicit debug-artifact

IDE. Gradle. Script

• KT-39542 EA-218043: java.util.NoSuchElementException: No element of given type found (GradleBuildRootsManager)
• KT-41283 Gradle scripts unable to support 1.4 language level features yet

IDE. Inspections and Intentions

• KT-41264 Disable “Redundant inner modifier” in 1.4.10
• KT-41395 Inspection description misses a space (needs to be lowercase)

IDE. REPL

• KT-40898 REPL: “IllegalAccessError: tried to access field” caused by log4j

IDE. Wizards

• KT-38921 New project wizard: Backend/Console applications template with Groovy DSL generates build.gradle with KotlinCompile instead of compileKotlin

JavaScript

• KT-38059 Support arrays passed as named arguments to varargs
• KT-40964 KJS / IR: don't generate “import” (short names) for external interfaces
• KT-41081 KJS IR: nativeGetter, nativeSetter, nativeInvoke are not supported

Libraries

• KT-41320 Actual kotlin.test annotation typealiases are inaccessible in modular environment

Middle-end. IR

• KT-41324 IR: “Compilation failed: null” caused by StackOverflowError in compiler in multi-module project

Native. C and ObjC Import

• KT-39762 cinterop on 1.4-M2 doesn't include @Deprecated Kotlin declaration for C declaration it fails to import

Native. ObjC Export

• KT-39206 New line characters in @Deprecated annotation cause syntax error in Kotlin/native exported header
• KT-40976 “Unrecognized selector sent to instance” exception invoking suspending lambda from Swift in Native iOS project

Reflection

• KT-40842 “AssertionError: Built-in class kotlin.Any is not found” on java modular run

Tools. Compiler Plugins

• KT-41321 Upgrading to 1.4.0 fails compiling native with is not bound error

Tools. Gradle. Multiplatform

• KT-41083 Transitive dependency on an MPP with host-specific source sets fails to resolve: “Couldn't resolve metadata artifact...”

Tools. Gradle. Native

• KT-40834 Cannot build Kotlin Multiplatform project on Windows 10 64-bit when the Cocoapods plugin is applied

Tools. Scripts

• KT-35925 REPL: Springboot autoconfiguration problem (META-INF/spring.factories not found ?)

Tools. kapt

• KT-41313 kapt 1.4.0 throws “ZipException: zip END header not found”, when Graal SVM jar in classpath

1.4.0

Compiler

New Features

• KT-23729 Provide a way to generate JVM default method bodies in interfaces delegating to DefaultImpls
• KT-30330 Introduce KotlinNothingValueException and throw it instead of NPE on expressions of type Nothing
• KT-38435 Support suspend conversion on callable references in JVM backend

Fixes

• KT-35483 NI: compatibility mode
• KT-39728 Declarations from kotlin.reflect resolved to expect-classes even in JVM modules in IDE
• KT-40153 REPL IDE services completion fails on imports completion
• KT-40404 Mixed named/positional arguments: argument can be passed twice
• KT-40544 NI: “TYPE_MISMATCH: Required: MutableList<out T!> Found: List” caused by Java interface function
• KT-40555 NI: Spread operator allows inferred nullable types
• KT-40646 NI: TYPE_MISMATCH: “inferred type is Unit but Observer was expected” caused by LieData.observe inference
• KT-40691 False positive CAPTURED_VAL_INITIALIZATION with EXACTLY_ONCE contract
• KT-40693 UnsupportedOperationException: no descriptor for type constructor of (CapturedType(out TResult)..CapturedType(out TResult)?)
• KT-40824 Usages of a typealias lose nullability and annotations in deserialization
• KT-40843 Unhandled exception for suspending methods that return Result type
• KT-40869 Recursion computation inside compiler resolve on a correct code
• KT-40893 Error “Captured values initialization is forbidden due to possible reassignment” when attempting to use the plusAssign operator with a java list inside an inline function
• KT-40919 kotlin.collections.ArrayDeque requires an explicit import when compiling with kotlinc 1.4-RC and -language-version 1.3
• KT-40920 Regression in JvmDefault: incorrect access to missing DefaultImpls on default methods in Java interface overriding Kotlin interface
• KT-40978 Prohibit using suspend functions as SAM in fun interfaces

Docs & Examples

• KT-35218 Fix misleading in JavaDoc for createTempDir/createTempFile
• KT-36981 Provide a visual illustration of source sets structure generated by ios(), watchos(), tvos() presets
• KT-38050 Language Guide: MPP reference: add sample of language settings for all roots instead of common root only

IDE

• KT-30265 IDE, MPP: False negative TYPE_PARAMETER_AS_REIFIED in common code
• KT-40494 UAST: “NoSuchElementException: No element of given type found” with use-site target annotation
• KT-40639 Shift IDE plugins updater numbers for Kotlin plugin

IDE. Code Style, Formatting

• KT-40636 Hard freeze on formatter: infinite recursion

IDE. Gradle Integration

• KT-30116 IDE: Unresolved reference in MPP module (androidMain source set) for annotation from common module (defined in commonMain and with JVM target)

IDE. Gradle. Script

• KT-34552 Deadlock in ScriptDefinitionsManager
• KT-40675 Gradle build file is not highlighted until navigating to symbol

IDE. JS

• KT-40461 Create new projects with kotlin.js.generate.executable.default=false

IDE. Script

• KT-39547 Kotlin script support freezes IDEA
• KT-40242 gradle.kts: Deadlock in ScriptClassRootsUpdater

IDE. Wizards

• KT-36153 New Project Wizard: provide more referential info on project structure editor screen
• KT-39904 New Project wizard 1.4: update Frontend Application to make it run with JS IR
• KT-40149 Gradle project wizard: templates for Kotlin/JS are not properly formatted

JavaScript

• KT-25859 JS: support function references to functions with vararg if expected type ends with repeated vararg element type
• KT-40083 K/JS-IR: java.lang.IllegalStateException: has not acquired a symbol yet
• KT-40892 KJS, IR: Unresolved references on importing classes from kotlinx-nodejs

Libraries

• KT-39051 Libraries native artifacts are published without sources

Tools. Gradle

• KT-27816 Provide a possibility to specify intermediate source sets between platform-agnostic and platform-specific test source sets
• KT-37720 Replace ArtifactTransform with TransformAction
• KT-40559 Adding the stdlib by default triggers warning in the Android Gradle Plugin

Tools. Gradle. JS

• KT-40093 Incorrect updating version of Kotlin/JS dependencies in package.json

Tools. Gradle. Multiplatform

• KT-27320 Provide a way to reuse same sources for similar Native target
• KT-40058 NPE from mpp gradle plugin on kotlinx.benchmarks

Tools. Gradle. Native

• KT-40801 Gradle CocoaPods integration: Cannot change a framework name

1.4-RC

Backend. Native

• KT-40209 java.lang.UnsupportedOperationException: org.jetbrains.kotlin.ir.declarations.impl.IrValueParameterImpl@76484173
• KT-40367 Kotlin/Native-Swift interop (iOS): Array member initialization failing in release builds

Compiler

Fixes

• KT-31025 Type mismatch when callable reference is resolved with a functional expected type and SAM conversion
• KT-37388 Consider relaxing rules about inferring Nothing inside special constructions (if, try, when)
• KT-37717 NI: “IllegalStateException: Error type encountered” with @BuilderInference
• KT-38427 New inference in branched conditions (if, when) results in odd behavior with inconsistent compiler warnings and runtime errors
• KT-38899 NI: False positive IMPLICIT_NOTHING_TYPE_ARGUMENT_IN_RETURN_POSITION leads to NPE
• KT-39468 NI: overload resolution ambiguity between functions passing T and Foo<T> with a contravariant receiver
• KT-39618 NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER: unable to infer generic type on @BuilderInference annotated lambda parameter with receiver type
• KT-39633 NI: Incorrect type parameter instantiation based on contravariant type argument
• KT-39691 NI: Missing SAM conversion for nullable lambda
• KT-39860 Make Kotlin binaries publicly available (set KotlinCompilerVersion.IS_PRE_RELEASE = false)
• KT-39900 NI: Incorrect type inference in a lambda returning Unit
• KT-39925 New JVM default compilation mode doesn't check that JVM target is 1.8
• KT-39943 Write information about all-compatibility mode in metadata
• KT-39953 NI: ClassCastException “cannot be cast to java.lang.Void” with if-else in return statement in ANdroid project
• KT-40045 NI: lambda’s receiver type isn't inferred properly
• KT-40057 NI: provideDelegate org.jetbrains.kotlin.codegen.CompilationException: Back-end (JVM) Internal error: wrong bytecode generated for static initializer
• KT-40060 NI: postponed variable from the builder inference flows to back-end and leads to throw an exception
• KT-40112 Kotlin Gradle DSL: COMPATIBILITY_WARNING on kotlin.sourceSets block
• KT-40113 Kotlin Gradle DSL: “Expression ‘main’ cannot be invoked as a function” for distributions.main DSL block
• KT-40128 Introduce compiler key to disable compatibility resolution mechanism for new inference features
• KT-40151 NI: postponed variable isn't substituted for top-level CR inside builder inference
• KT-40214 AbstractMethodError in gradle subplugin which is used in Android app
• KT-40234 Deprecation level “hidden” has no effect on callable reference argument
• KT-40247 NI: false positive “function should be called from coroutine or another suspend function” for suspend invoke operator in try-catch
• KT-40254 Rewrite at slice with two callable reference arguments
• KT-40269 NI: “disabled Unit conversions” error has appeared on green code
• KT-40337 NI: false positive “function should be called from coroutine or another suspend function” for suspend invoke operator in when block
• KT-40406 Prohibit reflection on adapted callable references

IDE

• KT-39968 Paths in KotlinJavaRuntime library aren't updated after you run IDE from a different directory
• KT-39989 NullPointerException when opening Kotlin facets in Project Structure dialog in IDEA 192
• KT-40311 Create change_notes for 1.4 in IDE plugin description

IDE. Debugger

• KT-39808 (CoroutineDebugger) Doesn't start with kotlinx-coroutines-core >= 1.3.6
• KT-40073 (CoroutineDebugger) Change minimum supported kotlinx.coroutines version to 1.3.8*
• KT-40172 Restored frame variables isn't shown for suspended coroutines
• KT-40635 Coroutines Debugger: make IDE plugin accept coroutines 1.3.8-rc* versions as well

IDE. Gradle Integration

• KT-38744 No dependency between Android test and commonTest source sets with kotlin.mpp.enableGranularSourceSetsMetadata=true
• KT-39037 ‘None of the consumable configurations have attributes’ in MPP IDE import with transitive project dependency on self

IDE. Gradle. Script

• KT-31137 IntelliJ would get very slow when editing gradle buildSrc(using the kotlin dsl)
• KT-36078 Gradle Kotlin script context is not reloaded when gradle/wrapper/gradle-wrapper.properties file is changed
• KT-39317 ISE “Calling invokeAndWait from read-action leads to possible deadlock.” on importing simple Gradle-based project in nightly IJ

IDE. Inspections and Intentions

• KT-28662 Inspection to flag usage of the wrong Transient annotation on Kotlin Serializable class
• KT-34209 Switch default behaviour in 1.4 for insertion (to build script) via quick fix of the compiler option enabling inline classes
• KT-36131 Suggest to add a missing module dependency on an unresolved reference in Kotlin code
• KT-37462 Add “Add dependency to module” quickfix in multimodule Maven project
• KT-39869 Add whole project migration usages of kotlin.browser.* & kotlin.dom.* to kotlinx.browser.* & kotlinx.dom.* respectively

IDE. Wizards

• KT-40004 New Project wizard 1.4+: no https://dl.bintray.com/kotlin/kotlinx repository is added for kotlinx-html
• KT-40037 New Project wizard: update Ktor version
• KT-40092 Wizard: the templates panel on mac OS is too wide
• KT-40232 New Wizard: Android Sdk path doesn't have backslash escaping on Windows
• KT-40371 New Project Wizard: Frontend Application / Library results in broken run configuration
• KT-40377 New Project Wizard: Frontend Application defines NPM dependencies that are unnecessary with Kotlin 1.4-RC+
• KT-40378 New Project Wizard: Frontend Application, Disabling JavaScript test framework has no effect
• KT-40407 Wizard: do not add stdlib by default for Gradle projects in wizard

JS. Tools

• KT-39984 Update dukat version in toolchain near to release of 1.4-RC

JavaScript

• KT-32186 Make sure K/JS Reflection API documentation is correct and fix it.
• KT-37563 K/JS: stacktrace is not captured for exceptions without primary constructor inherited from Exception/Error
• KT-37752 Generated typescript incorrect for constructors of derived classes
• KT-37883 KJS: Generated TypeScript uses ‘declare’ rather than ‘export’
• KT-38771 JS: support non-reified type parameters in typeOf
• KT-39873 Update Kotlin JavaScript wrappers due to NON_EXPORTABLE_TYPE diagnostic introduction
• KT-40126 [JS / IR] NPE while compiling interfaces with invoke which is passed as a delegate
• KT-40216 KJS / IR: AssertionError caused by an anonymous object in the dependency project

Libraries

• KT-33069 StringBuilder common functions
• KT-35972 Add contract to builder functions
• KT-37101 Mark following api with DeprecatedSinceKotlin(“1.4”)
• KT-38360 Make sure that JB libraries correctly define their npm deps and republish them (after KT-30619)
• KT-38817 ‘capitalize’ should convert digraphs to title case
• KT-40168 Remove StringBuilder.capacity from common and JS parts

Middle-end. IR

• KT-40520 Assert during fake-override generation

Tools. Commonizer

• KT-40199 Commonizer loses nullability of abbreviated types

Tools. Compiler Plugins

• KT-40036 Add diagnostic that shows is serialization plugin compatible with serialization-runtime

Tools. Gradle

• KT-39755 [KJS / Gradle / Legacy mode] Directory with whitespace is not processed
• KT-39809 Kotlin Gradle plugin: ServiceConfigurationError: org.jetbrains.kotlin.gradle.plugin.KotlinGradleSubplugin: Provider org.jetbrains.kotlin.gradle.internal.AndroidSubplugin not a subtype
• KT-39977 Collect statistics of used -Xjvm-default options
• KT-40300 Fail the build if in MPP plugin no targets configured

Tools. Gradle. JS

• KT-38170 Investigate how to improve migration experience from pre 1.4.0 DSL to the new one
• KT-39654 Default CSS settings in webpack has priority over user's settings
• KT-39842 Kotlin/JS Gradle DSL: peerNpm dependency fails
• KT-40048 [Gradle, JS] Deprecate kotlin-frontend plugin
• KT-40067 [Gradle, JS] Public package.json for mixed JS/TS project
• KT-40210 Fail the build when Kotlin/JS target is not (properly) configured
• KT-40320 Gradle JS: make migration to the new Gradle DSL smoother

Tools. Gradle. Multiplatform

• KT-32239 Custom configurations inside Kotlin JVM Gradle projects can't properly resolve multiplatform dependencies
• KT-39897 [Commonizer] Fast-pass for library fragments absent for some targets

Tools. J2K

• KT-39739 J2K: Access is allowed from event dispatch thread with IW lock only

Tools. kapt

• KT-34604 KAPT: Flaky NPE through org.jetbrains.kotlin.kapt3.base.ProcessorLoader.doLoadProcessors
• KT-36302 TypeTreeVisitor.visitMemberSelect IllegalStateException: node.sym must not be null on JDK 11
• KT-39876 KAPT: Serialization of classpath structure is incorrect if there are dependencies between types in jar/dir

1.4-M3

Compiler

New Features

• KT-23575 Deprecate with replacement and SinceKotlin
• KT-38652 Do not generate optional annotations to class files on JVM
• KT-38777 Hide Throwable.addSuppressed member and prefer extension instead

Performance Improvements

• KT-38489 Compilation of kotlin html DSL increasingly slow
• KT-28650 Type inference for argument type is very slow if several interfaces with a type parameter is used as an upper bound of a type parameter

Fixes

• KT-15971 Incorrect bytecode generated when inheriting default arguments not from the first supertype
• KT-25290 NI: “AssertionError: If original type is SAM type, then candidate should have same type constructor” on out projection of Java class
• KT-28672 Contracts on calls with implicit receivers
• KT-30279 Support non-reified type parameters in typeOf
• KT-31908 NI: CCE on passing lambda to function which accepts vararg SAM interface
• KT-32156 New inference issue with generics
• KT-32229 New inference algorithm not taking into account the upper bound class
• KT-33455 Override equals/hashCode in functional interface wrappers
• KT-34902 AnalyzerException: Argument 1: expected I, but found R for unsigned types in generic data class
• KT-35075 AssertionError: “No resolved call for ...” with conditional function references
• KT-35468 Overcome ambiguity between typealias kotlin.Throws and the aliased type kotlin.jvm.Throws
• KT-35494 NI: Multiple duplicate error diagnostics (in IDE popup) with NULL_FOR_NONNULL_TYPE
• KT-35681 Wrong common supertype between raw and integer literal type leads to unsound code
• KT-35937 Error “Declaration has several compatible actuals” on incremental build
• KT-36013 Functional interface conversion not happens on a value of functional type with smart cast to a relevant functional type
• KT-36045 Do not depend on the order of lambda arguments to coerce result to Unit
• KT-36448 NI: fix tests after enabling NI in the compiler
• KT-36706 Prohibit functional interface constructor references
• KT-36969 Generate @NotNull on instance parameters of Interface$DefaultImpls methods
• KT-37058 Incorrect overload resolution ambiguity on callable reference in a conditional expression with new inference
• KT-37120 [FIR] False UNRESOLVED_REFERENCE for public and protected member functions and properties which are declared in object inner class
• KT-37149 Conversion when generic specified by type argument of SAM type
• KT-37249 false TYPE_MISMATCH when When-expression branches have try-catch blocks
• KT-37341 NI: Type mismatch with combination of lambda and function reference
• KT-37436 AME: “Receiver class does not define or inherit an implementation of the resolved method” in runtime on usage of non-abstract method of fun interface
• KT-37510 NI infers java.lang.Void from the expression in a lazy property delegate and throws ClassCastException at runtime
• KT-37541 SAM conversion with fun interface without a function fails on compiling and IDE analysis in SamAdapterFunctionsScope.getSamConstructor()
• KT-37574 NI: Type mismatch with Kotlin object extending functional type passed as @FunctionalInterface to Java
• KT-37630 NI: ILT suitability in a call is broken if there are CST calculation and calling function's type parameters
• KT-37665 NI: applicability error due to implicitly inferred Nothing for returning T with expected type
• KT-37712 No extension receiver in functional interface created with lambda
• KT-37715 NI: VerifyError: Bad type on operand stack with varargs generic value when type is inferred
• KT-37721 NI: Function reference with vararg parameter treated as array and missing default parameter is rejected
• KT-37887 NI: Smart casting for Map doesn't work if the variable is already “smart casted”
• KT-37914 NI: broken inference for a casting to subtype function within the common constraint system with this subtype
• KT-37952 NI: improve lambdas completion through separation the lambdas analysis into several steps
• KT-38069 Callable reference adaptation should have dependency on API version 1.4
• KT-38143 New type inference fails when calling extension function defined on generic type with type arguments nested too deep
• KT-38156 FIR Metadata generation
• KT-38197 java.lang.OutOfMemoryError: Java heap space: failed reallocation of scalar replaced objects
• KT-38259 NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER for provideDelegate
• KT-38337 Map delegation fails for inline classes
• KT-38401 FIR: protected effective visibility is handled unprecisely
• KT-38416 FIR: infinite loop in BB coroutine test ‘overrideDefaultArgument.kt’
• KT-38432 FIR: incorrect effective visibility in anonymous object
• KT-38434 Implement resolution of suspend-conversion on FE only, but give error if suspend conversion is called
• KT-38437 [FIR] String(CharArray) is resolved to java.lang.String constructor instead of kotlin.text.String pseudo-constructor
• KT-38439 NI: anonymous functions without receiver is allowed if there is an expected type with receiver
• KT-38473 FIR: ConeIntegerLiteralType in signature
• KT-38537 IllegalArgumentException: “marginPrefix must be non-blank string” with raw strings and space as margin prefix in trimMargin() call
• KT-38604 Implicit suspend conversion on call arguments doesn't work on vararg elements
• KT-38680 NSME when calling generic interface method with default parameters overriden with inline class type argument
• KT-38681 Wrong bytecode generated when calling generic interface method with default parameters overriden with primitive type argument
• KT-38691 NI: overload resolution ambiguity if take R and () -> R, and pass literal lambda, which returns R
• KT-38799 False positive USELESS_CAST for lambda parameter
• KT-38802 Generated code crashes by ClassCastException when delegating with inline class
• KT-38853 Backend Internal error: Error type encountered: Unresolved type for nested class used in an annotation argument on an interface method
• KT-38890 NI: false negative Type mismatch for values with fun keyword
• KT-39010 NI: Regression with false-positive smartcast on var of generic type
• KT-39013 202, ASM 8: “AnalyzerException: Execution can fall off the end of the code”
• KT-39260 “AssertionError: Unsigned type expected: Int” in range
• KT-39305 NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER: unable to infer deeply nested type bound when class implements generic interface
• KT-39408 Using unsigned arrays as generics fails in 1.4-M2 with class cast exception
• KT-39533 NI: Wrong overload resolution for methods with SAM converted function reference arguments
• KT-39535 NI: Inference fails for the parameters of SAM converted lambdas with type parameters
• KT-39603 Require explicit override in JVM default compatibility mode on implicit generic specialization of inherited methods in classes
• KT-39671 Couldn't inline method call ‘expectBody’
• KT-39816 NI:ClassCastException and no IDE error with provideDelegate when DELEGATE_SPECIAL_FUNCTION_MISSING in OI
• KT-32779 Rewrite at slice in array access resolution in coroutine inference
• KT-39387 Can't build Kotlin project due to overload resolution ambiguity on flatMap calls
• KT-39229 NI: resolution to wrong candidate (SAM-type against similar functional type)

Docs & Examples

• KT-36245 Document that @kotlin.native.ThreadLocal annotation doesn't work anywhere except in Kotlin/Native
• KT-37943 Conflicting overloads in the factory functions sample code in Coding Conventions Page

IDE

New Features

• KT-10974 Add Code Style: Import Layout Configuration Table
• KT-39065 “Join lines” should remove trailing comma on call site

Fixes

• KT-9065 Wrong result when move statement through if block with call with lambda
• KT-14757 Move statement up breaks code in function parameter list
• KT-14946 Move statement up/down (with Ctrl+Shift+Up/Down) messes with empty lines
• KT-15143 Kotlin: Colors&Fonts -> “Enum entry” should use Language Default -> Classes - Static field
• KT-17887 Moving statement (Ctrl/Cmd+Shift+Down) messes with use block
• KT-34187 UAST cannot get type of array access
• KT-34524 “PSI and index do not match” and IDE freeze with library import from square/workflow
• KT-35574 UAST: UBreakExpression in when expression should be UYieldExpression
• KT-36801 IDE: Unsupported language version value is represented with “latest stable” in GUI
• KT-37378 Remove IDE option “Enable new type inference algorithm...” in 1.4
• KT-38003 “Analyze Data Flow from Here” should work on parameter of abstract method
• KT-38173 Reified types do no have extends information
• KT-38217 Make Kotlin plugin settings searchable
• KT-38247 “IncorrectOperationException: Incorrect expression” through UltraLightUtils.kt: inlined string is not escaped before parsing
• KT-38293 Throwable: “‘codestyle.name.kotlin’ is not found in java.util.PropertyResourceBundle” at KotlinLanguageCodeStyleSettingsProvider.getConfigurableDisplayName()
• KT-38407 Drop components from plugin.xml
• KT-38443 No error on change in property initializer
• KT-38521 ISE: Loop in parent structure when converting a DOT_QUALIFIED_EXPRESSION with parent ANNOTATED_EXPRESSION
• KT-38571 Rework deprecated EPs
• KT-38632 Change the code style to official in tests

IDE. Code Style, Formatting

Fixes

• KT-24750 Formatter: Minimum blank lines after class header does nothing
• KT-31169 IDEA settings search fails to find “Tabs and Indents” tab in Kotlin code style settings
• KT-35359 Incorrect indent for multiline expression in string template
• KT-37420 Add setting to disable inserting empty line between declaration and declaration with comment
• KT-37891 Formatter inserts empty lines between annotated properties
• KT-38036 Use trailing comma setting does not apply to code example in Settings dialog
• KT-38568 False positive: weak warning “Missing line break” on -> in when expression
• KT-39024 Add option for blank lines before declaration with comment or annotation on separate line
• KT-39079 Trailing comma: add base support for call site
• KT-39123 Option Align 'when' branches in columns does nothing
• KT-39180 Move trailing comma settings in Other tab

IDE. Completion

• KT-18538 Completion of static members of grand-super java class inserts unnecessary qualifier
• KT-38445 Fully qualified class name is used instead after insertion of delay method

IDE. Debugger

Fixes

• KT-14057 Debugger couldn't step into Reader.read
• KT-14828 Bad step into/over behavior for functions with default parameters
• KT-36403 Method breakpoints don't work for libraries
• KT-36404 Evaluate: “AssertionError: Argument expression is not saved for a SAM constructor”
• KT-37486 Kotlin plugin keeps reference to stream debugger support classes after stream debugger plugin is disabled
• KT-38484 Coroutines Debugger: IAE “Requested element count -1 is less than zero.” is thrown by calling dumpCoroutines
• KT-38606 Coroutine Debugger: OCE from org.jetbrains.kotlin.idea.debugger.coroutine.proxy.mirror.BaseMirror.isCompatible
• KT-39143 NPE on setCurrentStackFrame to Kotlin inner compiled class content
• KT-39412 Failed to find Premain-Class manifest attribute when debugging main method with ktor
• KT-39634 (CoroutineDebugger) Agent doesn't start if using kotlinx-coroutines-core only dependency
• KT-39648 Coroutines debugger doesn't see stacktraces in case of the project has kotlinx-coroutines-debug dependency

IDE. Gradle Integration

Performance Improvements

• KT-39059 Poor performance of modifyDependenciesOnMppModules

Fixes

• KT-35921 Gradle Import fails with “Unsupported major.minor version 52.0” on pure Java project in case “Gradle JDK” is lower 1.8 and Kotlin plugin is enabled
• KT-36673 Gradle Project importing: move ModelBuilders and ModelProviders to kotlin-gradle-tooling jar
• KT-36792 IDEA 2020.1: Some module->module dependencies in HMPP project are missed after import from Gradle
• KT-37125 Imported modules structure for MPP project is displayed messy in UI in IDEA 2020.1
• KT-37428 NPE at KotlinFacetSettings.setLanguageLevel() on the first project import
• KT-38706 IDE Gradle import creates 4 JavaScript modules for MPP source sets with BOTH compiler type
• KT-38767 Published hierarchical multiplatform library symbols are unresolved in IDE (master)
• KT-38842 False positive [INVISIBLE_MEMBER] for internal declaration of commonMain called from commonTest
• KT-39213 IDE: references from MPP project to JavaScript library are unresolved, when project and library are compiled with “both” mode
• KT-39657 Language settings for intermediate source-sets are lost during import

IDE. Gradle. Script

New Features

• KT-34481 *.gradle.kts: use Intellij IDEA Gradle project sync mechanics for updating script configuration

Performance Improvements

• KT-34138 Deadlock in ScriptTemplatesFromDependenciesProvider
• KT-38875 Deadlock in ScriptClassRootsUpdater.checkInvalidSdks

Fixes

• KT-34265 Bogus “build configuration failed, run ‘gradle tasks’ for more information” message and other issues related to “script dependencies”
• KT-34444 *.gradle.kts: special storage of all scripts configuration on one file
• KT-35153 build.gradle.kts: scripts in removed subproject remain imported, but shouldn't
• KT-35573 Request for gradle build script configuration only after explicit click on notification
• KT-36675 move .gradle.kts ModelBuilders and ModelProviders to kotlin-gradle-tooling jar
• KT-37178 build.gradle.kts: Rework the notification for scripts out of project
• KT-37631 Unnecessary loading dependencies after opening build.gradle.kts after project import with Gradle 6
• KT-37863 Scanning dependencies for script definitions takes too long or indefinitely during Gradle import
• KT-38296 MISSING_DEPENDENCY_SUPERCLASS in the build.gradle.kts editor while Gradle runs Ok
• KT-38541 “Invalid file” exception in ScriptChangeListener.getAnalyzableKtFileForScript()
• KT-39104 “Gradle Kotlin DSL script configuration is missing” after importing project in IJ201, Gradle 6.3
• KT-39469 Gradle version is not updated in script dependencies if the version of gradle was changed in gradle-wrapper.properties
• KT-39771 Freeze 30s from org.jetbrains.kotlin.scripting.resolve.ApiChangeDependencyResolverWrapper.resolve on loading script configuration with Gradle 5.6.4

IDE. Inspections and Intentions

New Features

• KT-14884 Intention to add missing “class” keyword for enum and annotation top-level declarations
• KT-17209 Provide intention to fix platform declaration clash (CONFLICTING_JVM_DECLARATIONS)
• KT-24522 Suggest to move typealias outside the class
• KT-30263 Detect redundant conversions of unsigned types
• KT-35893 Support Inspection for unnecessary asSequence() call
• KT-38559 “Change JVM name” (@JvmName) quickfix: improve name suggester for generic functions
• KT-38597 Expand Boolean intention
• KT-38982 Add “Logger initialized with foreign class” inspection
• KT-39131 TrailingCommaInspection: should suggest fixes for call-site without warnings

Fixes

• KT-5271 Missing QuickFix for Multiple supertypes available
• KT-11865 “Create secondary constructor” quick fix always inserts parameter-less call to this()
• KT-14021 Quickfix to add parameter to function gives strange name to parameter
• KT-17121 “Implement members” quick fix is not suggested
• KT-17368 Don't highlight members annotated with @JsName as unused
• KT-20795 “replace explicit parameter with it” creates invalid code in case of overload ambiguities
• KT-22014 Intention “convert lambda to reference” should be available for implicit ‘this’
• KT-22015 Intention “Convert lambda to reference” should be available in spite of the lambda in or out of parentheses
• KT-22142 Intentions: “Convert to primary constructor” changes semantics for property with custom setter
• KT-22878 Empty argument list at the call site of custom function named “suspend” shouldn't be reported as unnecessary
• KT-24281 Importing of invoke() from the same file is reported as unused even if it isn't
• KT-25050 False-positive inspection “Call replaceable with binary operator” for ‘equals’
• KT-26361 @Deprecated “ReplaceWith” quickfix inserts ‘this’ incorrectly when using function imports
• KT-27651 ‘Condition is always true’ inspection should not be triggered when the condition has references to a named constant
• KT-29934 False negative Change type quickfix on primary constructor override val parameter when it has wrong type
• KT-31682 ‘Convert lambda to reference’ intention inside class with function which return object produces uncompilable code
• KT-31760 Implement Abstract Function/Property intentions position generated member improperly
• KT-32511 Create class quick fix is not suggested in super type list in case of missing primary constructor
• KT-32565 False positive “Variable is the same as ‘credentials’ and should be inlined” with object declared and returned from lambda
• KT-32801 False positive “Call on collection type may be reduced” with mapNotNull, generic lambda block and new inference
• KT-33951 ReplaceWith quickfix with unqualified object member call doesn't substitute argument for parameter
• KT-34378 “Convert lambda to reference” refactoring does not work for suspend functions
• KT-34677 False positive “Collection count can be converted to size” with Iterable
• KT-34696 Wrong ‘Redundant qualifier name’ for ‘MyEnum.values’ usage
• KT-34713 “Condition is always ‘false’”: quickfix “Delete expression” doesn't remove else keyword (may break control flow)
• KT-35015 ReplaceWith doesn't substitute parameters with argument expressions
• KT-35329 Replace ‘when’ with ‘if’ intention: do not suggest if ‘when’ is used as expression and it has no ‘else’ branch
• KT-36194 “Add braces to ‘for’ statement” inserts extra line break and moves the following single-line comment
• KT-36406 “To ordinary string literal” intention adds unnecessary escapes to characters in template expression
• KT-36461 “Create enum constant” quick fix adds after semicolon, if the last entry has a comma
• KT-36462 “Create enum constant” quick fix doesn't add trailing comma
• KT-36508 False positive “Replace ‘to’ with infix form” when ‘to’ lambda generic type argument is specified explicitly
• KT-36930 Intention “Specify type explicitly” adds NotNull annotation when calling java method with the annotation
• KT-37148 "Remove redundant .let call doesn't remove extra calls
• KT-37156 “Unused unary operator” inspection highlighting is hard to see
• KT-37173 “Replace with string templates” intention for String.format produces uncompilable string template
• KT-37181 Don't show “Remove redundant qualifier name” inspection on qualified Companion imported with star import
• KT-37214 “Convert lambda to reference” with a labeled “this” receiver fails
• KT-37256 False positive PlatformExtensionReceiverOfInline inspection if a platform type value is passed to a nullable receiver
• KT-37744 “Convert lambda to reference” inspection quick fix create incompilable code when type is inferred from lambda parameter
• KT-37746 “Redundant suspend modifier” should not be reported for functions with actual keyword
• KT-37842 “Convert to anonymous function” creates broken code with suspend functions
• KT-37908 “Convert to anonymous object” quickfix: false negative when interface has concrete functions
• KT-37967 Replace ‘invoke’ with direct call intention adds unnecessary parenthesis
• KT-37977 “Replace ‘invoke’ with direct call” intention: false positive when function is not operator
• KT-38062 Reactor Quickfix throws NotImplementedError for Kotlin
• KT-38240 False positive redundant semicolon with as cast and not unary operator on next line
• KT-38261 Redundant ‘let’ call removal leaves ?. operator and makes code uncompilable
• KT-38310 Remove explicit type annotation intention drops ‘suspend’
• KT-38492 False positive “Add import” intention for already imported class
• KT-38520 SetterBackingFieldAssignmentInspection throws exception
• KT-38649 False positive quickfix “Assignment should be lifted out of when” in presence of smartcasts
• KT-38677 Invalid psi tree after Lift assigment out of...
• KT-38790 “Convert sealed subclass to object” for data classes doesn't remove ‘data’ keyword
• KT-38829 ‘Remove redundant backticks’ can be broken with @ in name
• KT-38831 ‘Replace with assignment’ can be broken with fast code change
• KT-38832 “Remove curly braces” intention may produce CCE
• KT-38948 False positive quickfix “Make containing function suspend” for anonymous function
• KT-38961 “Useless call on collection type” for filterNotNull on non-null array where list return type is expected
• KT-39069 Improve TrailingCommaInspection
• KT-39151 False positive inspection to replace Java forEach with Kotlin forEach when using ConcurrentHashMap

IDE. JS

• KT-39275 Kotlin JS Browser template for kotlin dsl doesn't include index.html

IDE. KDoc

• KT-32163 Open Quick Documentation when cursor inside function / constructor brackets

IDE. Navigation

• KT-32245 Method in Kotlin class is not listed among implementing methods
• KT-33510 There is no gutter icon to navigate from actual to expect if expect and the corresponding actual declarations are in the same file
• KT-38260 Navigation bar doesn't show directories of files with a single top level Kotlin class
• KT-38466 Top level functions/properties aren't shown in navigation panel

IDE. Project View

• KT-36444 Structure view: add ability to sort by visibility
• KT-38276 Structure view: support visibility filter for class properties

IDE. REPL

• KT-38454 Kotlin REPL in IntelliJ doesn‘t take module’s JVM target setting into account

IDE. Refactorings

• KT-12878 “Change signature” forces line breaks after every parameter declaration
• KT-30128 Change Signature should move lambda outside of parentheses if the arguments are reordered so that the lambda goes last
• KT-35338 Move/rename refactorings mess up code formatting by wrapping lines
• KT-38449 Extract variable refactoring is broken by NPE
• KT-38543 Copy can't work to package with escaped package
• KT-38627 Rename package refactorings mess up code formatting by wrapping lines

IDE. Run Configurations

• KT-34516 Don't suggest incompatible targets in a drop-down list for run test gutter icon in multiplatform projects
• KT-38102 DeprecatedMethodException ConfigurationFactory.getId

IDE. Scratch

• KT-38455 Kotlin scratch files don‘t take module’s JVM target setting into account

IDE. Script

• KT-39791 Kotlin plugin loads VFS in the output directories

IDE. Structural Search

• KT-39721 Optimize Kotlin SSR by using the index
• KT-39733 Augmented assignment matching
• KT-39769 “When expressions” predefined template doesn't match all when expressions

IDE. Wizards

• KT-38673 New Project Wizard: multiplatform templates are generated having unsupported Gradle version in a wrapper
• KT-38810 Incorrect order of build phases in Xcode project from new wizard
• KT-38952 Remove old new_project_wizards
• KT-39503 New Project wizard 1.4+: release kotlinx.html version is added to dependencies with milestone IDE plugin
• KT-39700 Wizard: group project templates on the first step by the project type
• KT-39770 CSS Support in Kotlin wizards
• KT-39826 Fix Android app in New Template Wizard
• KT-39843 Change imports in JS/browser wizard

JS. Tools

• KT-32273 Kotlin/JS console error on hot reload
• KT-39498 Update dukat version in toolchain near to release of 1.4-M3

JavaScript

• KT-29916 Implement typeOf on JS
• KT-35857 Kotlin/JS CLI bundled to IDEA plugin can't compile using IR back-end out of the box
• KT-36798 KJS: prohibit using @JsExport on a non-top-level declaration
• KT-37771 KJS: Generated TypeScript does not recursively export base classes (can fail with generics)
• KT-38113 Review public API of JS stdlib for IR BE
• KT-38765 [JS / IR] AssertionError: class EventEmitter: Super class should be any: with nested class extending parent class
• KT-38768 KJS IR: generate ES2015 (aka ES6) classes

Libraries

New Features

• KT-11253 Function to sum long or other numeric property of items in a collection
• KT-28933 capitalize() with Locale argument in the JDK stdlib
• KT-34142 Create SortedMap with Comparator and items
• KT-34506 Add Sequence.flatMap overload that works on Iterable
• KT-36894 Support flatMapIndexed in the Collections API
• KT-38480 Introduce experimental annotation for enabling overload resolution by lambda result
• KT-38708 minOf/maxOf functions to return min/max value provided by selector
• KT-39707 Make some interfaces in stdlib functional

Performance Improvements

• KT-23142 toHashSet is suboptimal for inputs with a lot of duplicates

Fixes

• KT-21266 Add module-info for standard library artifacts
• KT-23322 Document ‘reduce’ operation behavior on empty collections
• KT-28753 Comparing floating point values in array/list operations ‘contains’, ‘indexOf’, ‘lastIndexOf’: IEEE 754 or total order
• KT-30083 Annotate KTypeProjection.STAR with JvmField in a compatible way
• KT-30084 Annotate functions in KTypeProjection.Companion with JvmStatic
• KT-31343 Deprecate old String <-> CharArray, ByteArray conversion api
• KT-34596 Add some validation to KTypeProjection constructor
• KT-35978 Review and remove experimental stdlib API status for 1.4
• KT-38388 Document fromIndex and toIndex parameters
• KT-38854 Gradually change the return type of collection min/max functions to non-nullable
• KT-39023 Document split(Pattern) extension differences from Pattern.split
• KT-39064 Introduce minOrNull and maxOrNull extension functions on collections
• KT-39235 Lift experimental annotation from bit operations
• KT-39237 Lift experimental annotation from common StringBuilder
• KT-39238 Appendable.appendRange - remove nullability
• KT-39239 Lift experimental annotation from String <-> utf8 conversion api
• KT-39244 KJS: update polyfills, all or most of them must not be enumerable
• KT-39330 Migrate declarations from kotlin.dom and kotlin.browser packages to kotlinx.*

Middle-end. IR

• KT-31088 need a way to compute fake overrides for pure IR
• KT-33207 Kotlin/Native: KNPE during deserialization of an inner class
• KT-33267 Kotlin/Native: Deserialization error for an “inner” extension property imported from a class
• KT-37255 Make psi2ir aware of declarations provided by compiler plugins

Reflection

• KT-22936 Not all things can be changed to createType yet, and now defaultType methods are starting to fail
• KT-32241 Move KType.javaType into stdlib from reflect
• KT-34344 KType.javaType implementation throws when invoked with a typeOf()
• KT-38491 IllegalArgumentException when using callBy on function with inline class parameters and default arguments
• KT-38881 Add KClass.isFun modifier of functional interfaces to reflection

Tools. Android Extensions

• KT-25807 Kotlin extension annotation @Parcelize in AIDL returns Object instead of original T

Tools. CLI

• KT-30211 Support a way to pass arguments to the underlying JVM in kotlinc batch scripts on Windows
• KT-30778 kotlin-compiler.jar contains shaded but not relocated kotlinx.coroutines
• KT-38070 Compiler option to bypass prerelease metadata incompatibility error
• KT-38413 Add JVM target bytecode version 14

Tools. Compiler Plugins

• KT-39274 [KJS / IR] Custom serializer for class without zero argument constructor doesn't compile

Tools. Gradle

• KT-25428 Kotlin Gradle Plugin: Use new Gradle API for Lazy tasks
• KT-34487 Gradle build fails with "Cannot run program “java”: error=7, Argument list too long
• KT-35957 MPP IC fails with “X has several compatible actual declarations” error
• KT-38250 Drop support for Gradle versions older than 5.3 in the Kotlin Gradle plugin

Tools. Gradle. JS

New Features

• KT-30619 Support NPM transitive dependencies in multi-platform JS target
• KT-38286 [Gradle, JS] Error handling on Webpack problems

Fixes

• KT-31669 Gradle/JS: rise error when plugin loaded more than once
• KT-32531 [Gradle/JS] Add scoped NPM dependencies
• KT-34832 [Kotlin/JS] Failed build after webpack run (Karma not found)
• KT-35194 Kotlin/JS: browserRun fails with “address already in use” when trying to connect to local server
• KT-35611 Kotlin Gradle plugin should report kotlin2js plugin ID as deprecated
• KT-35641 Kotlin Gradle plugin should report kotlin-dce-js plugin ID as deprecated
• KT-36410 JS: Collect stats about IR backend usage
• KT-36451 KJS Adding npm dependency breaks Webpack devserver reloading
• KT-37258 Kotlin/JS + Gradle: in continuous mode kotlinNpmInstall time to time outputs “ENOENT: no such file or directory” error
• KT-38109 [Gradle, JS] Error handling on Karma launcher problems
• KT-38331 Add an ability to control generating externals for npm deps individually
• KT-38485 [Gradle, JS] Unable to configure JS compiler with string
• KT-38683 Remove possibility to set NPM dependency without version
• KT-38990 Support multiple range versions for NPM dependencies
• KT-38994 Remove possibility to set NPM dependency with npm(org, name, version)
• KT-39109 ArithmeticException: “/ by zero” caused by kotlinNodeJsSetup task with enabled gradle caching on Windows
• KT-39210 Kotlin/JS: with both JS and MPP modules in the same project Gradle configuration fails on nodejs {} and browser {}
• KT-39377 Use standard source-map-loader instead of custom one

Tools. Gradle. Multiplatform

• KT-39184 Support publication of Kotlin-distributed libraries with Gradle Metadata
• KT-39304 Gradle import error java.util.NoSuchElementException: Key source set foo is missing in the map on unused source set

Tools. Gradle. Native

• KT-37514 CocoaPods Gradle plugin: Support building from terminal projects for several platforms
• KT-38440 Make error message about missing Podfile path for cocoapods integration actionable for a user
• KT-38991 Gradle MPP plugin: Enable parallel in-process execution for K/N compiler
• KT-39935 Support overriding the KotlinNativeCompile task sources
• KT-37512 Cocoapods Gradle plugin: Improve error logging for external tools

Tools. J2K

• KT-35169 Do not show “Inline local variable” popup during “Cleaning up code” phase of J2K
• KT-38004 J2K breaks java getter call in java code
• KT-38450 J2K should convert Java SAM interfaces to Kotlin fun interfaces

Tools. JPS

• KT-27458 The Kotlin standard library is not found in the module graph ... in a non-Kotlin project.
• KT-29552 Project is completely rebuilt after each gradle sync.

Tools. Scripts

• KT-37766 Impossible to apply compiler plugins onto scripts with the new scripting API

Tools. kapt

• KT-29355 Provide access to default values for primary constructor properties

1.4-M2

Compiler

New Features

• KT-37432 Do not include annotations fields into ‘visibility must be explicitly specified’ check in api mode

Performance Improvements

• KT-27362 Anonymous classes representing function/property references contain rarely used methods
• KT-35626 NI: Performance problem with many type parameters
• KT-36047 Compiler produces if-chain instead of switch when when subject captured as variable
• KT-36638 Use ‘java/lang/StringBuilder.append (C)Ljava/lang/StringBuilder;’ when appending single character in JVM_IR
• KT-37389 Avoid type approximation during generation constraints with EQUALITY kind
• KT-37392 Avoid substitution and type approximation for simple calls
• KT-37546 NI: high memory and CPU consumption due to creating useless captured types (storing in approximated types cache, unneeded computations)

Fixes

• KT-11265 Factory pattern and overload resolution ambiguity
• KT-27524 Inline class is boxed when used with suspend modifier
• KT-27586 ClassCastException occurs if the Result (or any other inline class) is returned from a lambda
• KT-30419 Use boxed version of an inline class in return type position for covariant and generic-specialized overrides
• KT-31163 FIR: consider replacing comparisons with compareTo calls and some additional intrinsics
• KT-31585 ClassCastException with derived class delegated to generic class with inline class type argument
• KT-31823 NI: Type mismatch with a star projection and UnsafeVariance
• KT-33119 Pre-increment for inline class wrapping Int compiles to direct increment instead of inc-impl
• KT-33715 Kotlin/Native: metadata compiler
• KT-34048 IllegalAccessError when initializing val property in EXACTLY_ONCE lambda
• KT-34433 NI: Type mismatch with a star projection and UnsafeVariance
• KT-35133 FIR Java: don't set ‘isOperator’ for methods with non-operator names
• KT-35234 ClassCastException with creating an inline class from a function reference of covariant or generic-specialized override
• KT-35406 Generic type implicitly inferred as Nothing with no warning
• KT-35587 Plain namespace strings in JvmNameResolver.PREDEFINED_STRINGS are prone to namespace changes during jar relocation.
• KT-36044 NI: premature fixation a type variable if there were nested lambdas (constraint source was the deepest lambda)
• KT-36057 [FIR] Incorrect smartcast
• KT-36069 NI: TYPE_MISMATCH caused by incorrect inference to Nothing
• KT-36125 Callable reference resolution ambiguity error is not displayed properly in the IDE
• KT-36191 IDE locks loading packages and editing file containing try keyword inside string template
• KT-36222 NI: Improve error message about nullability mismatch for a generic call
• KT-36249 NI doesn't use upper bound for T of called function during infer return type and as a result infer it to Any? if the resulting type was intersection type
• KT-36345 FIR: record argument mapping for use in back-end
• KT-36446 NI: “UnsupportedOperationException no descriptor for type constructor of IntegerLiteralType[Int,Long,Byte,Short]” with BuilderInference and delegate
• KT-36758 [FIR] Unresolved callable reference to member of local class
• KT-36759 [FIR] Unsupported callable reference resolution for methods with default parameters
• KT-36762 [FIR] Unresolved array.clone()
• KT-36764 [FIR] Bug in inference with DefinitelyNotNull types
• KT-36816 NI: definitely not-null (T!!) types in invariant positions don't approximate to T inside inference process
• KT-36819 NI: premature completion of lambdas, which are passed somewhere
• KT-36850 Incorrect private visibility of sealed class constructors
• KT-36856 Throwing exception when there is inheritance in Kotlin from Java class, which contains methods with the same JVM descriptors
• KT-36879 Introduce FIR_IDENTICAL in diagnostic tests
• KT-36881 FIR: completion don't runs for return expressions
• KT-36887 [FIR] Unresolved member in nested lambda in initializer
• KT-36905 [FIR] Unresolved in lambda in default argument position
• KT-36953 AssertionError: “Unsigned type expected: null” when there is a range with an unsigned type
• KT-37009 FIR: Bound smart-cast lost
• KT-37027 FIR: Wrong projection on spread + varargs on non-final types
• KT-37038 NI: redundant lambda's arrow breaks CST calculation for extension lambdas
• KT-37043 NI: inference T to Any? if there was elvis between Java out-type and reified materialize for this type without out projection
• KT-37066 [FIR] Wrong type inference for lambdas
• KT-37070 [FIR] Unresolved parameters of outer lambda in scope of inner lambda
• KT-37087 “IllegalStateException: Can't find method ‘invoke()’” for mutable property reference in default value of an inline function parameter
• KT-37091 [FIR] Wrong inferred type of when-expression if when-argument is not-null-asserted and type is not specifies explicitly
• KT-37176 [FIR] Incorrect resolution mode for statements of block
• KT-37302 Unexpected conversion:Int constant inferred to Long in when expression
• KT-37327 FIR: Smartcast problem
• KT-37343 NI: definitely not null types pre-approximation is inconsistent with OI
• KT-37380 NI: broken some code with def not null types due to skip needed constraints
• KT-37419 NI: UNRESOLVED_REFERENCE_WRONG_RECEIVER is reported in case lambda with receiver is returned from when expression
• KT-37434 Kotlin/JS, Kotlin/Native: fun interfaces: SAM conversion to Kotlin interface is not compiled with RESOLUTION_TO_CLASSIFIER
• KT-37447 Expression from annotation entry in value parameter inside value parameter should be marked as USED_AS_EXPRESSION
• KT-37453 Type arguments not checked to be empty for candidates with no declared parameters
• KT-37488 [FIR] Incorrect exhaustiveness checking for branches with equals to object that implements sealed class
• KT-37497 NI: ‘super’ is not an expression, it can not be used as a receiver for extension functions
• KT-37530 NI: instantiation of abstract class via callable reference argument causes run time InstantiationError
• KT-37531 NI: callable reference argument with left hand side type parameter causes frontend exception
• KT-37554 NI: Nothing is inferred incorrectly with elvis return
• KT-37579 NI: inconsistent behaviour with OI around implicit invoke convention after safe call with additional implicit receiver
• KT-37604 “VerifyError: Call to wrong method” in ‘invoke’ for adapted callable reference to constructor with coercion to Unit
• KT-37621 NI: type variable is inferred to Nothing if the second branch was Nothing and there was upper bound for a type parameter
• KT-37626 NI: builder inference with expected type breaks class references resolution for a class with parameters
• KT-37627 NI: wrong order of the type variable fixation (Nothing? against a call with lambda)
• KT-37628 NI: wrong approximation of type argument to star projection during common super type calculation
• KT-37644 NI: appeared exception during incorporation of a captured type into a type variable for elvis resolve
• KT-37650 NI: it's impossible to infer a type variable with the participation of a wrapped covariant type
• KT-37718 False positive unused parameter for @JvmStatic main function in object
• KT-37779 ClassCastException: Named argument without spread operator for vararg parameter causes code to crash on runtime
• KT-37832 In MPP, subtypes of types defined in legacy libraries, like stdlib, cannot properly resolve on the consumer side receviing both
• KT-37861 Capturing an outer class instance in a default parameter of inner class constructor causes VerifyError
• KT-37986 Return value of function reference returning inline class mapped to ‘java.lang.Object’ is not boxed properly
• KT-37998 ‘!!’ operator on safe call of function returning inline class value causes CCE at runtime
• KT-38042 Allow kotlin.Result as a return type only if one enabled inline classes explicitly
• KT-38134 NI: Type mismatch with a star projection and UnsafeVariance
• KT-38298 Inconsistent choice of candidate when both expect/actual are available (affects only enableGranularSourceSetMetadata)
• KT-38661 NI: “Cannot infer type variable TypeVariable” with lambda with receiver
• KT-38668 Project with module dependency in KN, build fails with Kotlin 1.3.71 and associated libs but passes with 1.3.61.
• KT-38857 Class versions V1_5 or less must use F_NEW frames.
• KT-39113 “AssertionError: Uninitialized value on stack” with EXACTLY_ONCE contract in non-inline function and lambda destructuring
• KT-28483 Override of generic-return-typed function with inline class should lead to a boxing
• KT-37963 ClassCastException: Value of inline class represented as ‘java.lang.Object’ is not boxed properly on return from lambda

Docs & Examples

• KT-35231 toMutableList documentation is vague

IDE

Performance Improvements

• KT-30541 EDT Freeze after new Kotlin Script creation
• KT-35050 Significant freezes due to findSdkAcrossDependencies()
• KT-37301 Freeze when “Optimize Imports” in KotlinImportOptimizer
• KT-37466 Invalidate partialBodyResolveCache on OCB
• KT-37467 PerFileAnalysisCache.fetchAnalysisResults
• KT-37993 Do not resolve references if paste code is located in the same origin
• KT-38318 Freezes in IDEA

Fixes

• KT-27935 Functional typealias with typealias in type parameters causes UnsupportedOperationException in TypeSignatureMappingKt (IDEA analysis)
• KT-31668 Complete statement for class declaration: add ‘()’ to supertype
• KT-33473 UAST: References to local variable are resolved to UastKotlinPsiVariable
• KT-34564 Kotlin USimpleNameReferenceExpression for annotation parameter resolves to null for compiled Kotlin classes
• KT-34973 Light class incorrectly claiming ambiguous method call from Java when one overload is synthetic
• KT-35801 UAST: UnknownKotlinExpression for valid Kotlin annotated expression
• KT-35804 UAST: Annotations missing from catch clause parameters
• KT-35848 UAST: ClassCastException when trying to invoke UElement for some wrapped PsiElements
• KT-36156 Kotlin annotation attributes have blue color whereas white in Java
• KT-36275 UAST: UCallExpression::resolve returns null for local function calls
• KT-36717 Fix failing light class tests after switching plugin to language version 1.4
• KT-36877 Message bundles for copy paste are missed in 201
• KT-36907 IDE: -Xuse-ir setting on facet level does not affect highlighting
• KT-37133 UAST: Annotating assignment expression sometimes leads to UnknownKotlinExpression
• KT-37312 “Implement members” intention put function in the primary constructor if there are unused brackets in class
• KT-37613 Uast: no parameters in reified method
• KT-37933 Rare NPE in ProjectRootsUtilKt.isKotlinBinary [easy fix]
• KT-38081 Configure kotlin in project produces IDE error “heavy operation and should not be call on AWT thread”
• KT-38354 HMPP. IDE. Dependency leakage from leaf native to shared native module
• KT-38634 IDE: Error on opening MPP project in 1.3.72 after opening it in 1.4-M2

IDE. Code Style, Formatting

• KT-37870 “Remove trailing comma” action stops working after applying and cancelling it

IDE. Completion

• KT-36808 Delete Flow.collect from autocompletion list or make it least prioritized
• KT-36860 Provide convenient completion of extension functions from objects
• KT-37395 Invalid callable reference completion of member extension

IDE. Debugger

• KT-34906 Implement Coroutine Debugger
• KT-35392 Debugger omits meaningful part of the stacktrace even with disabled filter
• KT-36215 Coroutines debugger tab is empty in Android Studio
• KT-37238 Coroutines Debugger: dump creation fails every time
• KT-38047 Coroutines Debugger: Assertion failed: “Should be invoked in manager thread, use DebuggerManagerThreadImpl” on moving to source code from suspended coroutine in project without debugger jar in classpath
• KT-38049 Coroutines Debugger: NPE “null cannot be cast to non-null type com.sun.jdi.ObjectReference” is thrown by calling dumpCoroutines
• KT-38487 Any Field Watch interaction causes a MissingResourceException

IDE. Decompiler, Indexing, Stubs

• KT-37896 IAE: “Argument for @NotNull parameter ‘file’ of IndexTodoCacheManagerImpl.getTodoCount must not be null” through KotlinTodoSearcher.processQuery()

IDE. Gradle Integration

• KT-33809 With kotlin.mpp.enableGranularSourceSetsMetadata=true, IDE misses dependsOn-relation between kotlin and android sourceSets, leading to issues with expect/actual matching
• KT-36354 IDE: Gradle import from non-JVM projects: dependency to output artifact is created instead of module dependency
• KT-38037 UnsupportedOperationException on sync gradle Kotlin project with at least two multiplatform modules

IDE. Gradle. Script

• KT-36763 Drop modification stamp for scripts after project import
• KT-37237 Script configurations should be loaded during project import in case of errors
• KT-38041 Do not request for script configuration after VCS update

IDE. Inspections and Intentions

New Features

• KT-3262 Inspection “Inner class could be nested”
• KT-15723 Add ‘Convert to value’ quickfix for property containing only getter
• KT-34026 Add “Remove argument” quick fix for redundant argument in constructor call
• KT-34332 Add “Remove argument” quick fix for redundant argument in function call
• KT-34450 Convert function to property intention should be also displayed on fun keyword
• KT-34593 Invert ‘if’ condition: Invert String.isNotEmpty should be String.isEmpty
• KT-34819 Inspection: report useless elvis “?: return null”
• KT-37849 Support ReplaceWith for supertypes call

Performance Improvements

• KT-37515 Deadlock

Fixes

• KT-12329 “invert if” inserts unnecessary ‘continue’ for statement inside a loop with ‘continue’
• KT-17615 “Convert parameter to receiver” changes this to this@ < no name provided >
• KT-20868 IntelliJ says method from anonymous inner class with inferred interface type is not used even though it is
• KT-20907 Secondary constructor is marked as unused by IDE when called by typealias
• KT-22368 “Convert to block body” intention incorrectly formats closing brace
• KT-23510 “Remove parameter” quick fix keeps lambda argument when it's out of parentheses
• KT-27601 False positive “Unused import directive” for extension function used in KDoc
• KT-28085 “Convert receiver to parameter” introduces incorrect this@class in lambda
• KT-30028 “Convert parameter to receiver” introduces wrong ‘this’ qualifier for extension lambda receiver
• KT-31601 “Remove redundant let call” changes semantics by introducing multiple safe calls
• KT-31800 False positive “never used” with function in private val object expression
• KT-31912 QF “Convert to anonymous object” do nothing on SAM-interfaces
• KT-32561 “Property can be declared in constructor” causes another warning
• KT-32809 Convert parameter to receiver inserts wrong qualifiers for this (when nothing needs to be changed)
• KT-34371 “Surround with lambda” quickfix is not available for suspend lambda parameters.
• KT-34640 Replace ‘if’ with ‘when’ leads to copy comment line above when from another if
• KT-36225 KNPE: CodeInliner.processTypeParameterUsages with ReplaceWith for inline reified generic function
• KT-36266 NPE when invoking Lift return out of if/when after intention becomes inapplicable but still beeing shown
• KT-36296 False negative “Redundant SAM-constructor” with multiple SAM arguments
• KT-36367 False negative “Redundant SAM-constructor” for kotlin functions
• KT-36368 False negative “Redundant SAM-constructor” for fun interfaces in kotlin
• KT-36395 False positive “Redundant SAM-constructor” with two java interfaces extending one another
• KT-36411 “Put parameters on separate lines” and “Put parameters on one line” actions do not respect trailing comma
• KT-36482 “Add JvmOverloads annotation” intention is still suggested for annotation's parameters
• KT-36686 Implement members quickfix puts the implementation before the data class if it already has a body
• KT-36685 “Convert to a range check” transform hex range to int if it is compared with “Less” or “Greater”
• KT-36707 False positive redundant companion object on calling companion object members
• KT-36735 Inspection ‘Replace ‘toString’ with string template’ miss curly braces and generates wrong code for constructor calls
• KT-36834 Convert use-site targets and usages with convert property to fun intention
• KT-37213 “Move to top level” intention does not update imports for extension functions
• KT-37496 False positive “Remove redundant backticks” for multiple underscores variable name
• KT-37502 False positive “redundant lambda arrow” with inline generic function with reified type in object and anonymous parameter name
• KT-37508 “Convert receiver to parameter” breaks code in anonymous objects (this@ < no name provided >)
• KT-37576 Kotlin InspectionSuppressor not being called for the kotlin's inspections
• KT-37749 “Convert to anonymous object” intention is suggested for Java SAM conversion, but not for Kotlin
• KT-37781 “Add modifier” intention/quickfix works incorrectly with functional interfaces
• KT-37893 i18n: Incorrect quickfix name “Lift return out of '”

IDE. KDoc

• KT-37361 Support for showing rendered doc comments in editor

IDE. Libraries

• KT-36276 IDE: references to declarations in JavaScript KLib dependency are unresolved
• KT-37562 IDE: references to JavaScript KLib dependency are unresolved, when project and library are compiled with “both” mode

IDE. Navigation

• KT-18472 UI lockup on find usages
• KT-18619 Find Usages of element used via import alias does not show actual usage location
• KT-34088 Navigate | Implementations action doesn't show implementations of Java methods in Kotlin files if method has parameters referring to generic type
• KT-35006 IDE: “Navigate to inline function call site” from stack trace for nested inline call navigates to outer inline call
• KT-36138 628 second freeze when doing Find Usages on data class property
• KT-36218 Show Kotlin file members in navigation bar
• KT-37494 AnnotatedElementsSearch unable to find annotated property accessor

IDE. Project View

• KT-32886 Project tool window: Show Visibility Icons does nothing for Kotlin classes
• KT-37632 IDE error on project structure opening

IDE. Refactorings

Performance Improvements

• KT-37801 Renaming private property with common name is very slow

Fixes

• KT-22733 Refactor / Inline Function: fun with type parameter: KNPE at CodeInliner.processTypeParameterUsages()
• KT-27389 MPP: Refactoring “Move Class” does not change the package declaration
• KT-29870 Inline variable doesn't handle ‘when’ subject val correctly
• KT-33045 Cover Move Refactoring by statistics (FUS)
• KT-36071 Refactoring: Move top declaration implementation refactoring
• KT-36072 Empty files are removed on Refactor/Move action with turned off “Delete empty source files” option
• KT-36114 java.lang.NoClassDefFoundError exception on Refactor/Move of kotlin function if it is referenced in java
• KT-36129 java.lang.Throwable: Invalid file exception occurs on Refactor/Move of class from kotlin script
• KT-36382 Move file refactoring breaks ktor application config
• KT-36504 “Extract property” suggests potentially invalid name for new property
• KT-37637 KotlinChangeSignatureUsageProcessor broke Change Signature in Python plugin
• KT-37797 Useless “Value for new paramater” step in ‘Update usages to reflect signature changes’ for method with default parameter value
• KT-37822 Improve message “Inline all references and remove the kind”
• KT-38348 UL methods return signature without generic type parameters
• KT-38527 Move nested class to upper level fails silently: MissingResourceException

IDE. Script

• KT-37765 NCDFE KJvmCompiledModuleInMemory on running *.main.kts script

IDE. Tests Support

• KT-36716 With kotlin.gradle.testing.enabled=true, gradle console output gets extra ijLog messages
• KT-36910 There are no Run/Debug actions in context menu for non-JVM platform-specific test results
• KT-37037 [JS, Debug] Node.JS test debug doesn't stop on breakpoints

IDE. Wizards

New Features

• KT-36150 New Project Wizard: provide a way to connect with “dependsOn” relation the added project modules
• KT-36179 New Project Wizard: it's impossible to make a JVM target friendly to Java code in a multiplatform project

Fixes

• KT-35583 New Project wizard: don't suggest build systems which cannot be used
• KT-35585 New Project wizard: remember choices which have sense for many projects
• KT-35691 New Project wizard: artifact and group values are effectively ignored
• KT-35693 New Project wizard creates pom.xml / build.gradle referring to release Kotlin version only
• KT-36136 New Project Wizard: generated projects are missing m2 Gradle repository
• KT-36137 New Project Wizard: “multiplatform” shall be written as a single word, without the capital P in the middle
• KT-36155 New Project Wizard: show warning “Multiplatform project cannot be generated” only for MPP projects
• KT-36162 New Project Wizard: make the error messages in modules editor actionable
• KT-36163 New Project Wizard: remove trailing spaces in Android SDK Path automatically
• KT-36166 New Project Wizard: addition of Android target into a multiplatform project doesn't add a necessary minimal Android configuration
• KT-36169 New Project Wizard: Android-related projects failed to build
• KT-36176 New Project Wizard: module templates doesn't work for multiplatform projects
• KT-36177 New Project Wizard: it's impossible to add more than one target of JVM kind to a multiplatform project
• KT-36180 New Project Wizard: it's impossible to set target JVM version for a JVM module
• KT-36226 New Project Wizard: add Mobile Android/iOS project template
• KT-36267 New Project Wizard: flatten JVM targets list for multiplatform projects
• KT-36328 New Project wizard fails for certain templates with AE: “Wrong line separators” at KotlinFormattingModelBuilder.createModel()
• KT-37599 New Project Wizard: Open Kotlin Wizard via hyperlink
• KT-37667 New project wizard: implement new UI design
• KT-37674 Kotlin version in build files includes the IDEA version
• KT-38061 New Project wizard 1.4: do not allow choosing build system if corresponding IJ plugin is disabled
• KT-38567 New Project wizard 1.4+: Improve processing case when project with required path already exists
• KT-38579 New Project wizard 1.4+: multiplatform mobile application: build fails on lint task: Configuration with name ‘compileClasspath’ not found
• KT-38929 New project wizard: update libraries in project template according to kotlin IDE plugin version
• KT-38417 Enable new project wizard by-default
• KT-38158 java.lang.NullPointerException when try to create new project via standard wizard on Mac os

JS. Tools

• KT-36484 KotlinJS, MPP: Compilation throws “TypeError: b is not a function” only in production mode

JavaScript

• KT-31126 Invalid JS constructor call (primary ordinary -> secondary external)
• KT-35966 Make @JsExport annotation usable in common code
• KT-37128 KJS: StackOverflowException when using reified recursive bound for type parameter
• KT-37163 KJS: NullPointerException on using intersection type as a reified one
• KT-37418 Support AssociatedObjectKey and findAssociatedObject in JS IR BE

Libraries

New Features

• KT-8658 Add property delegates which call get/set on the given KProperty instance, e.g. a property reference
• KT-12448 Make @Suppress applicable for type parameters
• KT-22932 String.format should support null locale
• KT-23514 assertFailsWith should link unexpected exception as cause
• KT-23737 JS & MPP: Support exception cause and addSuppressed
• KT-25651 Add shuffle() to Array, ByteArray, IntArray, etc to match MutableList
• KT-26494 Create an interface with provideDelegate()
• KT-27729 Inherit ReadWriteProperty from ReadOnlyProperty
• KT-28290 Add the onEach extension function to the Array
• KT-29182 SIZE_BYTES/BITS for Float and Double
• KT-30372 Add associateWith to Array
• KT-33906 Add vararg overloads for maxOf/minOf functions
• KT-34161 Array.contentEquals/contentHashCode/contentToString should allow null array receiver and argument
• KT-35851 Add setOfNotNull function
• KT-36866 reduceIndexedOrNull
• KT-36955 stdlib: Reverse range and sortDescending range
• KT-37161 Add #onEachIndexed similar to #forEachIndexed
• KT-37603 Throwable.stackTraceToString: string with detailed information about exception
• KT-37751 Implement shuffled() method Sequences
• KT-37804 Add ‘fail’ in kotlin-test that allows to specify cause
• KT-37839 StringBuilder.appendLine in stdlib-common
• KT-37910 Support Media Source Extension (MSE) and Encrypted Media Extensions (EME) in Kotlin/Js
• KT-38044 Common Throwable.printStackTrace

Performance Improvements

• KT-37416 readLine() is very slow

Fixes

• KT-13887 Double/Float companion values such as NaN should be constants
• KT-14119 String.toBoolean() should be String?.toBoolean()
• KT-16529 Names of KProperty's type parameters are inconsistent with ReadOnlyProperty/ReadWriteProperty
• KT-36356 Specify which element Iterable.distinctBy(selector) retains
• KT-38060 runningFold and runningReduce instead of scanReduce
• KT-38566 Kotlin/JS IR: kx.serialization & ktor+JsonFeature: SerializationException: Can't locate argument-less serializer for class

Reflection

• KT-29969 Support optional vararg parameter in KCallable.callBy
• KT-37707 “IllegalStateException: superInterface.classLoader must not be null” on class, which implements “AutoCloaseable” interface, “isAccessible” property changing

Tools. CLI

• KT-37090 file does not exist: C:\Users\NK\DOWNLO~1\kotlin-compiler-1.3.61\kotlinc\bin\..\lib\kotlin-compiler.jar" from standalone compiler on Windows

Tools. Gradle

• KT-35447 Warnings should be piped to stderr when using allWarningsAsErrors = true
• KT-35942 User test Gradle source set code cannot reach out internal members from the production code
• KT-36019 Implement Gradle DSL for explicit API mode

Tools. Gradle. JS

New Features

• KT-32017 Kotlin/JS in MPP: support changing the generated JS file name in Gradle DSL
• KT-32721 [Gradle, JS] CSS Support for browser
• KT-36843 [Gradle, JS, IR] Configure JS Compiler Type through DSL
• KT-37207 Allow to use npm dependency from a local directory
• KT-38056 [Gradle, JS] Group tasks by browser and node

Fixes

• KT-32466 kotlinNpmResolve fails in the case of composite build
• KT-34468 Consider custom versions while parsing yarn.lock
• KT-36489 [Gradle, JS, IR]: Correct naming for both compilers
• KT-36784 Kotlin. JS. MPP – Cannot find project :js when using Gradle composite builds
• KT-36864 KJS. Composite build require JS plugin in root project
• KT-37240 KJS. Nondeterministic execution order for webpack scripts (from folder ‘webpack.config.d’)
• KT-37582 Kotlin/JS: KotlinWebpack non-nullable properties are shown as nullable in Gradle configuration
• KT-37587 KJS. Karma ignore dynamically created webpack patches
• KT-37635 [Gradle, JS] Webpack devtool provide enum for only 2 variants
• KT-37636 [Gradle, JS] Extract package.json from klib
• KT-37762 [Gradle, JS] Actualize Node and Yarn versions in 1.4
• KT-37988 [Gradle, JS] Bump NPM versions on 1.4-M2
• KT-38051 [Gradle, JS] browserDistribution doesn't provide outputs
• KT-38519 JS Compiler per project without additional import

Tools. Gradle. Multiplatform

• KT-36674 allMetadataJar task fails if there is an empty intermediate source set in a multiplatform project with native targets
• KT-38746 In HMPP, compilation of a shared-native source set could be mistakenly disabled
• KT-39094 Provide a way to pass custom JVM args to commonizer from Gradle

Tools. Gradle. Native

• KT-25887 Kotlin Native gradle build fail with endorsed is not supported. Endorsed standards and standalone APIs on jdk > 8 & CLion
• KT-36721 Deduce a fully qualified unique_name in klib manifest from something like group name
• KT-37730 Native part of multiplatform build fails with “unresolved reference” errors if there is a local and external module with the same name
• KT-38174 Kotlin/Native: Disable platform libraries generation at the user side by default

Tools. J2K

Fixes

• KT-34965 Convert function reference copied from function call
• KT-35593 New J2K: method‘s names don’t change between functions declared in Number.java and Number.kt
• KT-35897 J2K converts private enum constructors to internal constructors and produces NON_PRIVATE_CONSTRUCTOR_IN_ENUM error
• KT-36088 J2K: StackOverflowError when trying to convert Java class with recursive type bound
• KT-36149 J2K: PsiInvalidElementAccessException: Element class com.intellij.psi.impl.source.tree.CompositeElement of type DOT_QUALIFIED_EXPRESSION
• KT-36152 J2K: RuntimeException: Couldn't get containingKtFile for ktElement
• KT-36159 J2K: ClassCastException if constructor contains a super() call and class extends from Kotlin class
• KT-36190 J2K: Wrong property name generation when getter for non-boolean value starts with ‘is’
• KT-36891 j2k: Fail with java.lang.NoClassDefFoundError when converting array
• KT-37052 new J2K: Java private function is converted to private open top-level function
• KT-37620 new J2K: IndexOutOfBoundsException (DefaultArgumentsConversion.applyToElement) with overloaded function with vararg parameter
• KT-37919 new J2K: Redundant line feeds when converting function

Tools. JPS

• KT-37159 A Typo (forgotten space) in build output in Circular dependencies warning description

Tools. Scripts

• KT-30086 ThreadDeath when running kotlin scripts using jsr223
• KT-37558 Scripts: implicit receivers don't work correctly when using CompiledScriptJarsCache
• KT-37823 Consecutive invocations of main.kts throw a KotlinReflectionNotSupportedError

1.4-M1

Compiler

New Features

• KT-4240 Type inference possible improvements: analyze lambda with expected type from the outer call
• KT-7304 Smart-casts and generic calls with multiple bounds on type parameters
• KT-7745 Support named arguments in their own position even if the result appears as mixed
• KT-7770 SAM for Kotlin classes
• KT-8834 Support function references with default values as other function types
• KT-10930 Expected type isn't taken into account for delegated properties
• KT-11723 Support coercion to Unit in callable reference resolution
• KT-14416 Support of @PolymorphicSignature in Kotlin compiler
• KT-16873 Support COERSION_TO_UNIT for suspend lambdas
• KT-17643 Inferring type of Pair based on known Map type
• KT-19869 Support function references to functions with vararg if expected type ends with repeated vararg element type
• KT-21178 Prohibit access of protected members inside public inline members
• KT-21368 Improve type inference
• KT-25866 Iterable.forEach does not accept functions that return non-Unit values
• KT-26165 Support VarHandle in JVM codegen
• KT-27582 Allow contracts on final non-override members
• KT-28298 Allow references to generic (reified) type parameters in contracts
• KT-31230 Refine rules for allowed Array-based class literals on different platforms: allow Array::class everywhere, disallow Array<...>::class on non-JVM
• KT-31244 Choose Java field during overload resolution with a pure Kotlin property
• KT-31734 Empty parameter list required on Annotations of function types
• KT-33990 Type argument isn't checked during resolution part
• KT-33413 Allow ‘break’ and ‘continue’ in ‘when’ statement to point to innermost surrounding loop
• KT-34743 Support trailing comma in the compiler
• KT-34847 Lift restrictions from kotlin.Result

Fixes

• KT-2869 Incorrect resolve with ‘unsafe call error’ and generics
• KT-3630 Extension property (generic function type) does not work
• KT-3668 Infer type parameters for extension ‘get’ in delegated property
• KT-3850 Receiver check fails when type parameter has another parameter as a bound
• KT-3884 Generic candidate with contradiction is preferred over matching global function
• KT-4625 Poor error highlighting when assigning not matched type to index operator
• KT-5449 Wrong resolve when functions differ only in the nullability of generic type
• KT-5606 “Type mismatch” in Java constructor call with SAM lambda and vararg parameter
• KT-6005 Type inference problem in sam constructors
• KT-6591 Overloaded generic extension function call with null argument resolved incorrectly
• KT-6812 Type inference fails when passing a null instead of a generic type
• KT-7298 Bogus type inference error in generic method call translated from Java
• KT-7301 Type inference error in Kotlin code translated from Java
• KT-7333 Type inference fails with star-projections in code translated from Java
• KT-7363 Kotlin code with star-projections translated from Java does not typecheck
• KT-7378 3-dimension array type inference fail
• KT-7410 Call resolution error appears only after adding non-applicable overload
• KT-7420 Type inference sometimes infers less specific type than in Java
• KT-7758 Type of lambda can't be infered
• KT-8218 Wrong ‘equals’ for generic types with platform type and error type
• KT-8265 Non-typesafe program is compiled without errors
• KT-8637 Useless diagnostics for type parameters with unsafe nullability
• KT-8966 Smart casts don't work with implicit receiver and extension on type parameter with bounds
• KT-10265 Type inference problem when using sealed class and interfaces
• KT-10364 Call completeCall on variable before invoke resolution
• KT-10612 java.util.Comparator.comparing type inference
• KT-10628 Wrong type mismatch with star projection of inner class inside use-site projected type
• KT-10662 Smartcast with not-null assertion
• KT-10681 Explicit type arguments not taken into account when determining applicable overloads of a generic function
• KT-10755 Not “least” common super-type is selected for nested ‘if’ result in presence of multiple inheritance
• KT-10929 Type inference based on receiver type doesn't work for delegated properties in some cases
• KT-10962 Wrong resolution when argument has unstable DataFlowValue
• KT-11108 RxJava failed platform type inference
• KT-11137 Java synthetic property does not function for a type with projection
• KT-11144 UninferredParameterTypeConstructor exception during build
• KT-11184 Type inference failed for combination of safe-call, elvis, HashSet and emptySet
• KT-11218 Type inference incorrectly infers nullable type for type parameter
• KT-11323 Type inference failed in call with lambda returning emptyList
• KT-11331 Unexpected “Type inference failed” in SAM-conversion to projected type
• KT-11444 Type inference fails
• KT-11664 Disfunctional inference with nullable type parameters
• KT-11894 Type substitution bug related platform types
• KT-11897 No error REIFIED_TYPE_FORBIDDEN_SUBSTITUTION on captured type
• KT-11898 Type inference error related to captured types
• KT-12036 Type inference failed
• KT-12038 non-null checks and inference
• KT-12190 Type inference for TreeMap type parameters from expected type doesn't work when passing comparator.
• KT-12684 A problem with reified type-parameters and smart-casts
• KT-12833 ‘it’ does not work in typed containers of lambdas
• KT-13002 “Error type encountered: UninferredParameterTypeConstructor” with elvis and when
• KT-13028 cast with star on on type with contravariant generic parameter makes the compiler crash
• KT-13339 Type inference failed for synthetic Java property call on implicit smart cast receiver
• KT-13398 “Type T is not a subtype of Any”
• KT-13683 Type inference incorporation error when passed null into not-null parameter
• KT-13721 Type inference fails when function arguments are involved
• KT-13725 Type inference fails to infer type with array as a generic argument
• KT-13800 Type inference fails when null passed as argument (related to common system)
• KT-13934 Callable reference to companion object member via class name is not resolved
• KT-13964 Unknown descriptor on compiling invoke operator call with generic parameter
• KT-13965 Invoke operator called on extension property of generic type has incorrect parameter type
• KT-13992 Incorrect TYPE_INFERENCE_UPPER_BOUND_VIOLATED
• KT-14101 Type inference failed on null
• KT-14174 Compiler can't infer type when it should be able to
• KT-14351 Internal error with uninferred types for compiling complicated when expression
• KT-14460 Smartcast isn't considered as necessary in the last expression of lambda
• KT-14463 Missing MEMBER_PROJECTED_OUT error after smartcast with invoke
• KT-14499 Type inference fails even if we specify T explicitly
• KT-14725 kotlin generics makes agera's compiled repositories unusable
• KT-14803 Weird smart cast absence in lazy delegate
• KT-14972 Type inference failed: wrong common supertype for types with several subtypes
• KT-14980 Type inference for nullable type in if statement
• KT-15155 False “No cast needed” warning for conversion to star-projected type
• KT-15185 Inference for coroutines not work in case where we have suspend function with new coroutine inside
• KT-15263 Kotlin can't infer the type of a multiple bounded method
• KT-15389 Type inference for coroutines in 1.1-M04
• KT-15394 Support coercion to Unit for last statement for suspend lambda
• KT-15396 Type inference for last statement in coroutine
• KT-15488 Type inference not working on generic function returning generic type in lambda result
• KT-15648 Better use of overladed functions with nullables
• KT-15922 TYPE_INFERENCE_CONFLICTING_SUBSTITUTION for function reference
• KT-15923 Internal error: empty intersection for types
• KT-16247 Overload resolution ambiguity with intersection types and method references
• KT-16249 Can't call generic method with overloaded method reference when non-generic overload exists
• KT-16421 Remove @ParameterName annotation from diagnostic messages
• KT-16480 Wrong “Type mismatch” for variable as function call
• KT-16591 Type inferencing doesn't consider common base class of T of multiple Foo function parameters
• KT-16678 Overload resolution ambiguity on println()
• KT-16844 Recursive dependency] (DeferredType) error on code generation.
• KT-16869 Cannot infer type parameter S in fun <S, T : S?> f(x: S, g: (S) -> T): T
• KT-17018 “Rewrite at slice LEXICAL_SCOPE” for ‘when’ with function reference inside lambda
• KT-17048 Compilation exception: error type encountered in some combination of when/elvis with multiple inheritance
• KT-17340 Type inference failed on overloaded method reference with expected KFunction
• KT-17386 Smart cast on LHS of callable reference doesn't work if expected type is nullable
• KT-17487 ReenteringLazyValueComputationException for interface with a subclass that has a property of interface type
• KT-17552 Call completed not running for elvis as last expression in lambda
• KT-17799 Smart cast doesn't work for callable reference (colon-colon operator)
• KT-17968 More type inference problems with Streams.collect
• KT-17995 No type mismatch with empty when expression inside lambda
• KT-18002 Issue with star projection for generic type with recursive upper bound
• KT-18014 Cannot use Comparator.comparing
• KT-18080 Type inference failed for generic method reference argument
• KT-18192 Type inference fails for some nested generic type structures
• KT-18207 Unexpected attempt to smart cast causes compile error
• KT-18379 Type inference failed although explicit specified
• KT-18401 Type mismatch when inferring out type parameter (related to callable reference)
• KT-18481 ReenteringLazyValueComputationException for recursive const declaration without explicit type
• KT-18541 Prohibit “tailrec” modifier on open functions
• KT-18790 function take the parameterized type with multi-bounds can't working
• KT-19139 Kotlin build error in Android Studio on << intent.putExtra(“string”, it.getString(“string”) >> inside “else if” block
• KT-19751 Nested conditionals break type inference when multiple types are possible for the expression
• KT-19880 An overload with nullable parameter is not resolved due to a smart cast attempt after assignment
• KT-19884 type inference with type parameter
• KT-20226 Return type ‘Any’ inferred for lambda with early return with integer literal in one of possible return values
• KT-20656 Callable reference breaks smart cast for next statement
• KT-20734 Invalid “Smart-cast impossible” when there are applicable extension and semi-applicable member
• KT-20817 Coroutine builder type inference does not take smart casts into account (confusing)
• KT-21060 ReenteringLazyValueComputationException during type inference
• KT-21396 if-else with a branch of type Nothing fails to infer receiver type
• KT-21463 Compiler doesn't take into accout a type parameter upper bound if a corresponding type argument is in projection
• KT-21607 Type inference fails with intermediate function
• KT-21694 Type inference failed for ObservableList
• KT-22012 Kotlin type deduction does not handle Java's <? super T> constructs
• KT-22022 ReenteringLazyValueComputationException when having cyclic references to static variables
• KT-22032 Multiple type parameter bounds & smart casts
• KT-22043 Report an error when comparing enum (==/!=/when) to any other incompatible type since 1.4
• KT-22070 Type inference issue with platform types and SAM conversion
• KT-22474 Type safety problem because of incorrect subtyping for intersection types
• KT-22636 Anonymous function can be passed as a suspending one, failing at runtime
• KT-22723 Inconsistent behavior of floating-point number comparisons
• KT-22775 Type inference failed when yielding smartcasted not null value from sequence
• KT-22885 Broken type safety with function variables caused by wrong subtyping check that includes intersection types
• KT-23141 Cannot resolve between two functions when only one of them accepts nullable parameter
• KT-23156 IDEA asking me to remove uninferable explicit type signature
• KT-23391 Bogus type inference error with smart cast, synthetic property and star projection
• KT-23475 Implicit invoke on property with generic functional return type resolves incorrectly
• KT-23482 Incorrect frontend behaviour for not inferred type for generic property with function type as result
• KT-23677 Incorrect error diagnostic for return types that coerced to ‘Unit’ inside lambda
• KT-23748 Erroneous type mismatch when call with @Exact annotation depends on non-fixed type variable
• KT-23755 Nested lambdas with nested types can cause false USELESS_CAST warning
• KT-23791 Explicit type argument leads to an error, while candidate is picked correctly without it
• KT-23992 Target prefixes for annotations on supertype list elements are not checked
• KT-24143 Type-checking error for generic functions
• KT-24217 Type inference for generic functions reference problem.
• KT-24237 Uninferred type parameter on variable with multiple smart casts in elvis
• KT-24317 Unnecessary non-null assertion inspection shown
• KT-24341 Compiler exception instead of error about “upper bound violated”
• KT-24355 Overload resolution ambiguity due to unstable smartcast
• KT-24458 Cannot solve “Conditional branch result is implicitly cast to Any” with List
• KT-24493 Incorrect error about Array unsupported
• KT-24886 Type inference failure in an if-else_if-else
• KT-24918 type inference not good enough for return type with involved if statement
• KT-24920 Type inference failure when using RxJava compose
• KT-24993 Inference for buildSequence/yield doesn't work for labeled lambdas
• KT-25063 List of Arrays - wrong type inferred if nullable involved
• KT-25268 Incorrect type inference (least upper bound of the types) in exhaustive when for Number
• KT-25294 Reactors Mono map function with Kotlin
• KT-25306 Make f(a = arrayOf(x)) equivalent to f(a = *arrayOf(x))
• KT-25342 Type inference: lazy with generic fails to infer
• KT-25434 Too eager smartcast cause type mismatch
• KT-25585 “Rewrite at slice LEXICAL_SCOPE” for if expression with callable reference inside lambda
• KT-25656 Short-hand array literal notation type inference fails in nested annotations
• KT-25675 return when leads to compiler error
• KT-25721 Type inference does not work in nested try catch
• KT-25827 NullPointerException in setResultingSubstitutor with a generic base class
• KT-25841 Collection type is inferred as Collection if the values returned from map function have an intersection common type
• KT-25942 Pass a parameter to generic function with several upper bounds
• KT-26157 Failed type inference for Delegates.observable parameter with a nullable property
• KT-26264 No smart cast on implicit receiver extension function call
• KT-26638 Check for repeatablilty of annotations doesn't take into account annotations with use-site target
• KT-26698 OnlyInputTypes doesn't work in presence of upper bound constraint
• KT-26704 Correct variable-as-function call fails to compile in case of function type dependent on variable type
• KT-27440 Infer lambda parameter type before lambda analysis in common system
• KT-27464 False negative type mismatch when a non-null assertion is used on a top-level var mutable variable
• KT-27606 Incorrect type inference when common supertype of enum classes is involved
• KT-27722 mapNotNull on List<Result> fails if T is not subtype of Any
• KT-27781 ReenteringLazyValueComputationException for anonymous object property referring to itself in overridden method
• KT-27799 Prohibit references to reified type parameters in annotation arguments in local classes / anonymous objects
• KT-28083 Nothing-call smart cast of a variable that a lambda returns does not affect the lambda's return type
• KT-28111 Type inference fails for return type of lambda with constrained generic
• KT-28242 Not-null assertion operator doesn't affect smartcast types
• KT-28264 Resulting type of a safe call should produce type that is intersected with Any
• KT-28305 “Error type encountered” with elvis operator, type argument and explicit Any type
• KT-28319 “resultingDescriptor shouldn't be null” for a star projection base class
• KT-28334 Smartcast doesn't work if original type is type with star projection and there was already another smartcast
• KT-28370 Var not-null smartcasts are wrong if reassignments are used inside catch section (in try-catch) or try section (in try-finally)
• KT-28424 Type annotations are not analyzed properly in several cases
• KT-28584 Complex condition fails smart cast
• KT-28614 “Error type encountered: UninferredParameterTypeConstructor”
• KT-28726 Recursion in type inference causes ReenteringLazyValueComputationException
• KT-28837 SAM conversion doesn't work for arguments of members imported from object
• KT-28873 Function reference resolution ambiguity is not reported
• KT-28999 Prohibit type parameters for anonymous objects
• KT-28951 “Error type encountered” with elvis operator, type argument and explicit Any type
• KT-29014 Unclear diagnostic for conditional branches coercion with multiple root interfaces and no common superclass
• KT-29079 ByteArray.let(::String) can not compile as the callable reference is resolved before the outer call
• KT-29258 Incorrect return type is used for analysis of an extension lambda (if its type is used as a generic parameter)
• KT-29330 NI: Multiple duplicate error messages in IDE popup with lambda argument
• KT-29402 Missed INLINE_FROM_HIGHER_PLATFORM diagnostic if inline function called from Derived class
• KT-29515 type inference fails to infer T of KFunction0 for most types
• KT-29712 Incorrect compiler warning, “No cast needed” for recursive type bound
• KT-29876 ReenteringLazyValueComputationException with usage of property inside lambda during assignment to that property
• KT-29911 Not-null smart cast fails inside inline lambda after safe call on generic variable with nullable upper bound
• KT-29943 Callable reference resolution ambiguity between a property and a function is reported incorrectly in function calls expecting KProperty1
• KT-29949 Cannot chose among overload as soon as nullable type is involved
• KT-30151 Any instead of Number is inferred as common super type of Int and Double
• KT-30176 Compiler can't infer correct type argument which blocks overload resolution
• KT-30240 Can't infer intersection type for a type variable with several bounds
• KT-30278 Retain star projections in typeOf
• KT-30394 Different behaviour in type inferences (bug in the old inference) when cast of variable of nullable type parameter to not-null is used
• KT-30496 Wrong infix generic extension function is chosen for null receiver
• KT-30550 Suspend modifier on a functional type changes resolution of return type
• KT-30892 IllegalStateException(UninferredParameterTypeConstructor) with return references to local function from if-else expression
• KT-30947 No smart cast on accessing generic class member with upper-bounded type argument
• KT-31102 Type mismatch in mixing lambda and callable reference
• KT-31151 “IllegalStateException: Error type encountered” with elvis, when and inheritance
• KT-31219 Type mismatch for delegated property depending on anonymous object
• KT-31290 overload resolution ambiguity with Iterable.mapTo()
• KT-31352 JvmName can't eliminate platform declaration clash of annotated properties
• KT-31532 Type inference for complex last expression in lambda
• KT-31540 Change initialization order of default values for tail recursive optimized functions
• KT-31594 No SETTER_PROJECTED_OUT diagnostic on synthetic properties from Java
• KT-31630 TYPE_INFERENCE_PARAMETER_CONSTRAINT_ERROR for generic function with callable reference argument
• KT-31654 False unnecessary non-null assertion (!!) warning inside yield call
• KT-31679 NI: Unresolved reference with delegated property and anonymous object
• KT-31739 Overload resolution ambiguity in generic function call with lambda arguments that take different parameter types
• KT-31923 Outer finally block inserted before return instruction is not excluded from catch interval of inner try (without finally) block
• KT-31968 New inference is using a more common system to infer types from nested elvis call than OI
• KT-31978 NI: changed precedence of elvis operator relative to equality operator
• KT-32026 Infer return type of @PolymorphicSignature method to void if no expected type is given
• KT-32087 “Remove explicit type arguments” inspection when function creates a lambda that calls a function with type argument
• KT-32097 NI: NON_APPLICABLE_CALL_FOR_BUILDER_INFERENCE when using awaitClose in channelFlow builder
• KT-32098 Kotlin 1.3.40 type inference mismatch between the IDE and the compiler
• KT-32151 Return arguments of lambda are resolved in common system while in OI aren't
• KT-32165 Cannot use ‘Nothing’ as reified type parameter,
• KT-32196 Inconsistency between compiler and inspection with mapNotNull
• KT-32203 NON_APPLICABLE_CALL_FOR_BUILDER_INFERENCE warning false-positive
• KT-32249 New inference breaks generic property delegate resolution
• KT-32250 New Type Inference fails for nullable field
• KT-32262 Type inference failed in presence of @JvmSuppressWildcards
• KT-32267 NI: “Overload resolution ambiguity. All these functions match.” with KFunction
• KT-32284 False positive “Redundant lambda arrow” with extension function returning generic with lambda type argument
• KT-32290 New Inference: old inference fails on nullable lambda from if-expression
• KT-32306 False positive Remove explicit type arguments when using generic return argument from lambda for delegated property
• KT-32358 NI: Smart cast doesn't work with inline function after elvis operator
• KT-32383 NI: listOf(…) infers to invalid type if different enums implementing the same interface are involved
• KT-32397 OI can't infer types when there are different lower and upper bounds in common system
• KT-32399 OI can't choose candidate with different lower and upper bounds
• KT-32425 No coercion to Unit by a return type of callable expression argument
• KT-32431 Nothing inferred for upper bound in parametric class
• KT-32449 IDE fails to report error: Expected type mismatch
• KT-32462 NI: “AssertionError: No resolved call” with callable reference
• KT-32497 Compiler Type inference fails when inferring type parameters (“Generics”) - IDE inference works
• KT-32507 IntelliJ Kotlin plugin not recognizing smart cast to non-nullable type
• KT-32501 type inference should infer nullable type if non-nullable doesn't work
• KT-32527 Cast required for Sequence.map when mapping between disjoint types
• KT-32548 OVERLOAD_RESOLUTION_AMBIGUITY with platform generic types
• KT-32595 NI: Overload resolution ambiguity for member function with type parameter with upper bounds and lambda parameter
• KT-32598 Kotlin 1.3.41 type inference problem
• KT-32654 Non-applicable call for builder inference with coroutines
• KT-32655 Kotlin compiler and IDEA plugin disagree on type
• KT-32686 New type inference algorithm infers wrong type when return type of when expression has a type parameter, and it's not specified in all cases
• KT-32788 No smartcast for an implicit “this” in old inference
• KT-32792 Bug in new type inference algorithm for Android Studio
• KT-32800 Problem with inlined getValue in Delegates, IDEA does not detect problem, but code doesn't compile
• KT-32802 Odd behaviour with smart-casting in exception block
• KT-32850 Invalid suggestion in Kotlin code
• KT-32866 tests in Atrium do not compile with new type inference
• KT-33012 Proper capturing of star projections with recursive types
• KT-33102 Fake overrides aren't created for properties
• KT-33152 Type inference fails when lambda with generic argument type is present
• KT-33166 NI: TYPE_MISMATCH for specific case with when expression and one branch throwing exception
• KT-33171 TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER with object convention invoke direct call on property delegation
• KT-33240 Generated overloads for @JvmOverloads on open methods should be final
• KT-33545 NI: Error type encountered: NonFixed: TypeVariable(T) (StubType)
• KT-33988 Low priority candidates doesn't match when others fail
• KT-34128 Internal compiler error ReenteringLazyValueComputationException in the absence of right parenthesis
• KT-34140 Function with contract doesn't smartcast return value in lambda
• KT-34314 There is no an error diagnostic about type inference failed (impossible to infer type parameters) on callable references
• KT-34335 A lambda argument without a type specifier is inferred to Nothing, if it's passed to a function, declaration of which contains vararg (e.g. Any)
• KT-34501 if-expression infers Any when Number? is expected
• KT-34708 Couldn't transform method node: emit$$forInline (try-catch in a Flow.map)
• KT-34729 NI: type mismatch error is missed for generic higher-order functions
• KT-34830 Type inference fails when using an extension method with “identical JVM signature” as method reference
• KT-34857 “Illegal resolved call to variable with invoke” with operator resolved to extension property invoke
• KT-34891 CompilationException: Failed to generate expression: KtLambdaExpression (Error type encountered)
• KT-34925 MPP, IDE: False positive warning NO_REFLECTION_IN_CLASS_PATH in common code
• KT-35020 “Type checking has run into a recursive problem” for overloaded generic function implemented using expression body syntax
• KT-35064 NI: The new inference has overload resolution ambiguity on passing a callable reference for extension functions (> 1 candidates)
• KT-35207 Incorrect generic signature in annotations when KClass is used as a generic parameter
• KT-35210 NI: OnlyInputTypes check fails for types with captured ones
• KT-35213 NI: overload resolution ambiguity for callable reference with defined LHS
• KT-35226 Forbid spread operator in signature-polymorphic calls
• KT-35306 Non-applicable call for builder inference for nested builder functions which return generic types that are wrapped.
• KT-35337 IllegalStateException: Failed to generate expression: KtLambdaExpression
• KT-35398 NI, IDE: Duplicate warning message JAVA_CLASS_ON_COMPANION in argument position
• KT-35469 Change behavior of signature-polymorphic calls to methods with a single vararg parameter, to avoid wrapping the argument into another array
• KT-35487 Type safety problem because of lack of captured conversion against nullable type argument
• KT-35494 NI: Multiple duplicate error diagnostics (in IDE popup) with NULL_FOR_NONNULL_TYPE
• KT-35514 Type inference failure with out type and if-else inside lambda
• KT-35517 TYPE_MISMATCH error duplication for not Boolean condition in if-expression
• KT-35535 Illegal callable reference receiver allowed in new inference
• KT-35578 Diagnostics are sometimes duplicated
• KT-35602 NI doesn't approximate star projections properly for self types
• KT-35658 NI: Common super type between Inv<A!>, Inv<A?> and Inv is Inv<out A?>, not Inv<A!> (as old inference)
• KT-35668 NI: the lack of fixing to Nothing problem (one of the bugs: the lack of smartcast through cast of Nothing? to Nothing after elvis)
• KT-35679 Type safety problem because several equal type variables are instantiated with a different types
• KT-35684 NI: “IllegalStateException: Expected some types” from builder-inference about intersecting empty types on trivial code
• KT-35814 Inference fails to infer common upper type for java types
• KT-35834 Do not declare checked exceptions in JVM bytecode when using delegation to Kotlin interfaces
• KT-35920 NI allows callable references prohibited in old inference
• KT-35943 NI: IllegalStateException: No error about uninferred type parameter
• KT-35945 Using Polymorphism and Type Inference the compiler fails having a Type with Type with Type
• KT-35992 Wrong overload resolution with explicit type arguments if KFunction and type parameter once nullable and once non-nullable
• KT-36001 “IllegalStateException: Error type encountered” with elvis in generic function
• KT-36002 KotlinFrontEndException: Exception while analyzing expression
• KT-36065 Type inference failed for generic function invoked on implicitly nullable variable created from Java
• KT-36066 Type inference problem in compiler
• KT-36101 False positive IMPLICIT_NOTHING_AS_TYPE_PARAMETER with suspend lambdas
• KT-36146 Drop support of language version 1.0/1.1, deprecate language version 1.2
• KT-36192 Redundant smart cast for overloaded functions
• KT-36202 NI: false positive “NON_APPLICABLE_CALL_FOR_BUILDER_INFERENCE” with elvis operator in lambda
• KT-36220 NI: false positive NON_APPLICABLE_CALL_FOR_BUILDER_INFERENCE if one use cannot resolve
• KT-36221 NI: UnsupportedOperationException: “no descriptor for type constructor” with vararg parameter when set or get methods of element passed as function reference
• KT-36264 NI: unstable smart cast changes results of call resolution
• KT-36279 OI: Type inference fails when omitting explicit name of the lambda parameter
• KT-36298 Failure to resolve return type of extension property on function literal
• KT-36317 TYPE_MISMATCH diagnostic error duplication for not Boolean condition in do-while-loop-statement
• KT-36338 Forbid IR backend usage with unsupported language / API version
• KT-36371 Incorrect null check with NI and builder inference in generic context
• KT-36644 Stop discrimination of prerelease compiler version in Kotlin plugin
• KT-36745 NI: “Expected some types” with unresolved class reference
• KT-36776 Treat special constructions (if, when, try) as a usual calls when there is expected type
• KT-36818 NI: the lack of smartcast from Nothing returning “when” branch
• KT-37123 Cycling lambda signature errors in Observable.combineLatest
• KT-37146 Type inference can't resolve plus operator
• KT-37189 Wrong type inferred with class with two types as argument
• KT-37295 NI: Passing function with wrong returning type by reference is not shown as error
• KT-37345 Wrong non-null type assertion when using Sequence and yield
• KT-37429 Type inference failed: Not enough information to infer parameter with java streams
• KT-37480 “None of the following candidates can be called” when compiling but no error in IDEA

IDE

• KT-33573 IDE runs platform-specific checkers on common code even if the project doesn't target the corresponding platform
• KT-35823 IDE settings: deprecated values of language / API version look like regular ones
• KT-35871 NPE in LightMethodBuilder
• KT-36034 Kotlin 1.3.70 creates file kotlinCodeInsightSettings.xml with user-level settings under .idea
• KT-36084 “Join lines” should remove trailing comma
• KT-36460 IDE highlighting: Undo on inspection breaks analysis inside top-level property initializer
• KT-36712 Use new annotation highlighting API
• KT-36917 Caret has incorrect position after pressing enter on line with named argument

IDE. Code Style, Formatting

• KT-36387 Formatter: “Chained Function Calls” formats property chains
• KT-36393 Incorrect trailing comma insertion for boolean operator expression
• KT-36466 Formatter: “Chained Function Calls” with “Wrap first call” wrap single method call

IDE. Completion

• KT-16531 Error type displayed in completion for the result of buildSequence
• KT-32178 Autocompletion of ‘suspend’ should not add the ‘fun’ keyword when writing a function type
• KT-34582 Remove kotlin.coroutines.experimental from autocompletion
• KT-35258 Completion problems with enabled MixedNamedArgumentsInTheirOwnPosition feature

IDE. Debugger

• KT-12016 Step over inside inline function lambda argument steps into inline function body
• KT-14296 Can't step over inlined functions of iterator
• KT-14869 Debugger: always steps into inlined lambda after returning from function
• KT-15652 Step over inline function call stops at Thread.dispatchUncaughtException() in case of exceptions
• KT-34905 Debugger: “Step over” steps into inline function body if lambda call splitted on several lines
• KT-35354 ClassCastException in evaluate window

IDE. Gradle. Script

• KT-36703 .gradle.kts: Change text for out of project scripts

IDE. Hints

• KT-37537 IDE is missing or swallowing keystrokes when hint popups are displayed

IDE. Hints. Parameter Info

• KT-14523 Weird parameter info tooltip for map.getValue type arguments

IDE. Inspections and Intentions

New Features

• KT-33384 Intention to switch between single-line/multi-line lambda
• KT-34690 Support intention Convert lambda to reference for qualified references
• KT-35639 False negative inspection “redundant internal modifier” inside private class
• KT-36256 Implement migration for WarningOnMainUnusedParameter
• KT-36257 Implement migration for ProhibitRepeatedUseSiteTargetAnnotations
• KT-36258 Implement migration for ProhibitUseSiteTargetAnnotationsOnSuperTypes
• KT-36260 Implement migration for ProhibitJvmOverloadsOnConstructorsOfAnnotationClasses
• KT-36261 Implement migration for ProhibitTypeParametersForLocalVariables
• KT-36262 Implement migration for RestrictReturnStatementTarget

Fixes

• KT-14001 “Convert lambda to reference” results in failed type inference
• KT-14781 Import of aliased type is inserted when deprecation replacement contains typealias
• KT-16907 “Convert to lambda reference” intention is erroneously shown for suspending lambda parameters, producing bad code
• KT-24869 False positive inspection “Redundant ‘suspend’ modifier”
• KT-24987 Implicit (unsafe) cast from dynamic to DONT_CARE
• KT-27511 “Remove explicit type arguments” suggestion creates incorrect code
• KT-28415 False positive inspection “Remove explicit type arguments” with a callable reference
• KT-30831 False positive Remove explicit type arguments with generic type constructor with init block
• KT-31050 False positive “Boolean literal argument without parameter name” inspection using expect class
• KT-31559 Type inference failed: Not enough information to infer parameter K
• KT-32093 NI: IDE suggests to use property access syntax instead of getter method
• KT-33098 False positive “Remove explicit type arguments” with “Enable NI for IDE” and Java generic class constructor invocation with nullable argument
• KT-33685 ReplaceWith does not add type parameter for function taking generic lambda with receiver
• KT-34511 kotlin.KotlinNullPointerException after using intention Replace Java Map.forEach with Kotlin's forEach for Map with Pairs as keys
• KT-34686 False positive “Constructor parameter is never used as a property” if property is used as a reference
• KT-35451 Type inference fails after applying false positive inspection "Remove explicit type arguments "
• KT-35475 Applying intention “Redundant curly braces in string template” for label references change semantic
• KT-35528 Intention Replace 'when' with 'if' produces wrong code if expression subject is a variable declaration
• KT-35588 Applying “Lift assignment out of ‘if’” for if statement that has lambda plus assignment and ‘return’ leads to type mismatch
• KT-35604 Too long quickfix message for “modifier ‘open’ is not applicable to ‘companion object’”
• KT-35648 False negative intention “Remove argument name” on named positional arguments
• KT-36160 False positive “Constructor has non-null self reference parameter” with vararg parameter of class
• KT-36171 intention “Replace ‘get’ call with indexing operator” works incorrectly with spread operator
• KT-36255 Implement migration tool for 1.4
• KT-36357 “Lift assignment out of ‘if’” breaks code for oneliner function
• KT-36360 OI: False positive “remove explicit type arguments” for SequenceScope leads to compiler failure with “Type inference failed”
• KT-36369 “To raw string literal” intention is not available if string content starts with newline symbol \n

IDE. Multiplatform

• KT-36978 Infinite “org.jetbrains.kotlin.idea.caches.resolve.KotlinIdeaResolutionException: Kotlin resolution encountered a problem while analyzing KtFile” exceptions in hierarchical multiplatform projects

IDE. Navigation

• KT-30628 Navigation from Java sources to calls on Kotlin function annotated with @JvmOverloads that have optional arguments omitted leads to decompiled code

IDE. Refactorings

New Features

• KT-26999 Inspection for unused main parameter in Kotlin 1.3
• KT-33339 Refactor / Move is disabled for Kotlin class selected together with Kotlin file

Fixes

• KT-22131 “Extract method” refactoring treats smart casted variables as non-local
• KT-24615 “Extract property” generates useless extension property
• KT-26047 Refactor -> Rename: Overridden method renaming in generic class doesn't rename base method
• KT-26248 “Refactor -> Inline variable” breaks callable references
• KT-31401 Refactor / Inlining function reference in Java method with Runnable argument produces compile error
• KT-33709 Inline variable: NONE_APPLICABLE with overloaded generic Java method with SAM conversion
• KT-34190 Inline Function: False positive error “not at the end of the body” with anonymous object
• KT-35235 Unable to move multiple class files to a different package
• KT-35463 ClassCastException during moving .kt file with one single class to the other folder in Android Studio
• KT-36312 Refactor Move refactoring to get it ready for MPP-related fixes

IDE. Run Configurations

• KT-34503 “Nothing here” is shown as a drop-down list for “Run test” gutter icon for a multiplatform test with expect/actual parts in platform-agnostic code
• KT-36093 Running Gradle java tests are broken for Gradle older than 4.0 (Could not set unknown property ‘testClassesDirs’ for task ‘:nonJvmTestIdeSupport’)

JavaScript

• KT-23284 Reified type arguments aren't substituted when invoking inline val value

Libraries

• KT-26654 Remove deprecated ‘mod’ operators
• KT-27856 Add contracts to Timing.kt lambdas
• KT-28356 Fail fast in Regex.findAll on an invalid startIndex
• KT-29748 Declare kotlin.reflect.KType in kotlin-stdlib-common
• KT-30360 Deprecate conversions of floating point types to integral types lesser than Int
• KT-32855 KTypeParameter is available in common code, but not available in Native
• KT-35216 <T : AutoCloseable?, R> T.use and <T : Closeable?, R> T.use should have contracts
• KT-36082 JS Regex.find does not throw IndexOutOfBoundsException on invalid start index
• KT-36083 Extract kotlin.coroutines.experimental.* packages to a separate compatibility artifact

Reflection

• KT-30071 Implement KTypeProjection.toString
• KT-35991 Embed Proguard/R8 rules in kotlin-reflect artifact jar

Tools. CLI

• KT-28475 java.sql module not available in kotlinc scripts on Java 9+ due to use of Bootstrap Classloader

Tools. Gradle. JS

• KT-34989 NodeJs is not re-downloaded if the node binary gets accidentally deleted
• KT-35465 Gradle, JS: Gradle tooling for IR compiler
• KT-36472 Kotlin/JS Gradle plugin iterates over all Gradle tasks, triggering their lazy configuration
• KT-36488 Gradle, JS, IR: Publishing from JS plugin

Tools. Gradle. Multiplatform

• KT-37264 In intermediate common source sets, internals are not visible from their dependsOn source sets during Gradle build

Tools. Gradle. Native

• KT-36804 In a project with Kotlin/Native targets and kotlinx.serialization, IDE import fails: Could not create task ‘...’. / Cannot change dependencies of configuration after it has been resolved.

Tools. J2K

• KT-20120 J2K: Java 9 forRemoval and since methods of Deprecated are not processed

Tools. Scripts

• KT-35414 Switch for -Xexpression to -expression/-e cli argument syntax for JVM cli compiler in 1.4

Recent ChangeLogs:

ChangeLog-1.3.X

ChangeLog-1.2.X

ChangeLog-1.1.X

ChangeLog-1.0.X