Cleanup comments, add test for default behavior (#772, #773)
diff --git a/generator/proto/nanopb.proto b/generator/proto/nanopb.proto
index b79267c..5e36eaa 100644
--- a/generator/proto/nanopb.proto
+++ b/generator/proto/nanopb.proto
@@ -148,10 +148,10 @@
   // The default value will probably change to false in nanopb-0.5.0.
   optional bool sort_by_tag = 28 [default = true];
 
-  // this affects the FT_DEFAULT (the default) field conversion strategy. A field
-  // that can become a static member of a c struct (e.g. int, bool, etc) will be a
-  // a static field. Fields with dynamic length are converted, to either a pointer or a callback.
-  // this defines wether it becomes a pointer or a callback.
+  // Set the FT_DEFAULT field conversion strategy.
+  // A field that can become a static member of a c struct (e.g. int, bool, etc)
+  // will be a a static field.
+  // Fields with dynamic length are converted to either a pointer or a callback.
   optional FieldType fallback_type = 29 [default = FT_CALLBACK]; 
 }
 
diff --git a/tests/fallback_type/SConscript b/tests/fallback_type/SConscript
index 22a7b1e..98dfd74 100644
--- a/tests/fallback_type/SConscript
+++ b/tests/fallback_type/SConscript
@@ -1,11 +1,7 @@
-# Test fallback type
+# Test fallback_type option
 
 Import("env")
-# the scons version on ubuntu honours this env - debians version does not
-# env['NANOPB_GENERATOR'] = env['NANOPB_GENERATOR'] + "-sfallback_type:FT_POINTER"
-# env.SetDefault(PROTOCFLAGS = "--plugin=protoc-gen-nanopb=foo")
 
-# so we also use an options file:
 env.NanopbProto(["fallback_type","fallback_type.options"])
 env.Object("fallback_type.pb.c")
 env.Match(['fallback_type.pb.h', 'fallback_type.expected'])
diff --git a/tests/fallback_type/fallback_type.expected b/tests/fallback_type/fallback_type.expected
index 3eff62b..05d72d0 100644
--- a/tests/fallback_type/fallback_type.expected
+++ b/tests/fallback_type/fallback_type.expected
@@ -1,2 +1,3 @@
 int32_t member1;
 char \*member2
+pb_callback_t member3
diff --git a/tests/fallback_type/fallback_type.options b/tests/fallback_type/fallback_type.options
index 29eddfa..8db3189 100644
--- a/tests/fallback_type/fallback_type.options
+++ b/tests/fallback_type/fallback_type.options
@@ -1 +1 @@
-fallback_type.proto fallback_type:FT_POINTER
\ No newline at end of file
+Message1.member2 fallback_type:FT_POINTER
diff --git a/tests/fallback_type/fallback_type.proto b/tests/fallback_type/fallback_type.proto
index 97d069b..2e1dc0a 100644
--- a/tests/fallback_type/fallback_type.proto
+++ b/tests/fallback_type/fallback_type.proto
@@ -4,5 +4,6 @@
 {
   required int32 member1 = 1; // must remain as int
   required string member2 = 2; // must become a pointer
+  required string member3 = 3; // must become pb_callback_t
 }