Ensure that stack traces are propagated more often in dart:io.

sdk/lib/io/io_sink.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.io;
 
 /**
  * Helper class to wrap a [StreamConsumer<List<int>>] and provide
  * utility functions for writing to the StreamConsumer directly. The
  * [IOSink] buffers the input given by all [StringSink] methods and will delay
@@ skipping 125 matching lines @@
 
   _StreamSinkImpl(this._target) {
     _doneFuture = _doneCompleter.future;
   }
 
   void add(T data) {
     if (_isClosed) return;
     _controller.add(data);
   }
 
-  void addError(error, [StackTrace stackTrace]) =>
-      _controller.addError(error, stackTrace);
+  void addError(error, [StackTrace stackTrace]) {
+    _controller.addError(error, stackTrace);
+  }
 
   Future addStream(Stream<T> stream) {
     if (_isBound) {
       throw new StateError("StreamSink is already bound to a stream");
     }
     _isBound = true;
     if (_hasError) return done;
     // Wait for any sync operations to complete.
     Future targetAddStream() {
       return _target.addStream(stream)
@@ skipping 31 matching lines @@
       if (_controllerInstance != null) {
         _controllerInstance.close();
       } else {
         _closeTarget();
       }
     }
     return done;
   }
 
   void _closeTarget() {
-    _target.close()
-        .then((value) => _completeDone(value: value),
-              onError: (error) => _completeDone(error: error));
+    _target.close().then(_completeDoneValue, onError: _completeDoneError);
   }
 
   Future get done => _doneFuture;
 
-  void _completeDone({value, error}) {
+  void _completeDoneValue(value) {
     if (_doneCompleter == null) return;
-    if (error == null) {
-      _doneCompleter.complete(value);
-    } else {
-      _hasError = true;
-      _doneCompleter.completeError(error);
-    }
+    _doneCompleter.complete(value);
     _doneCompleter = null;
   }
 
+  void _completeDoneError(error, StackTrace stackTrace) {
+    if (_doneCompleter == null) return;
+    _hasError = true;
+    _doneCompleter.completeError(error, stackTrace);
+    _doneCompleter = null;
+  }
+
   StreamController<T> get _controller {
     if (_isBound) {
       throw new StateError("StreamSink is bound to a stream");
     }
     if (_isClosed) {
       throw new StateError("StreamSink is closed");
     }
     if (_controllerInstance == null) {
       _controllerInstance = new StreamController<T>(sync: true);
       _controllerCompleter = new Completer();
       _target.addStream(_controller.stream)
           .then(
               (_) {
                 if (_isBound) {
                   // A new stream takes over - forward values to that stream.
                   _controllerCompleter.complete(this);
                   _controllerCompleter = null;
                   _controllerInstance = null;
                 } else {
                   // No new stream, .close was called. Close _target.
                   _closeTarget();
                 }
               },
-              onError: (error) {
+              onError: (error, stackTrace) {
                 if (_isBound) {
                   // A new stream takes over - forward errors to that stream.
-                  _controllerCompleter.completeError(error);
+                  _controllerCompleter.completeError(error, stackTrace);
                   _controllerCompleter = null;
                   _controllerInstance = null;
                 } else {
                   // No new stream. No need to close target, as it have already
                   // failed.
-                  _completeDone(error: error);
+                  _completeDoneError(error, stackTrace);
                 }
               });
     }
     return _controllerInstance;
   }
 }
 
 
 class _IOSinkImpl extends _StreamSinkImpl<List<int>> implements IOSink {
   Encoding _encoding;
@@ skipping 46 matching lines @@
 
   void writeln([Object obj = ""]) {
     write(obj);
     write("\n");
   }
 
   void writeCharCode(int charCode) {
     write(new String.fromCharCode(charCode));
   }
 }