CHANGELOG

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