SendPort does not preserve partial instantiation of closures

[mraleph]

If you send a partially instantiated closure over a send-port you will receive an uninstantiated function on another side.

[mkustermann]

/cc @aam Interested in looking at this?

[aam]

Sure, will do

[aam]

import 'dart:isolate';

class Cat {}

class Dog {}  

List<T> decodeFrom<T>(String s) {
  return List();
}

List<Dog> Function(String s) decodeFromDog = decodeFrom;
List<Cat> Function(String s) decodeFromCat = decodeFrom;

void main() async {
  final receivePort = ReceivePort();
  receivePort.listen((data) {
    print("Received $data");
    receivePort.close();
  });
  print("Sending $decodeFromDog");
  receivePort.sendPort.send(<dynamic>[decodeFromDog]);
}

$ dart sendfun.dart
Sending Closure: (String) => List<Dog> from Function 'decodeFrom': static.
Received [Closure: <T>(String) => List<T> from Function 'decodeFrom': static.]

Expectation is that Sending matches Received