Improve the error-propagation on socket streams

sdk/lib/io/socket_stream_impl.dart

 // Copyright (c) 2012, 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;
 
 class _SocketInputStream implements InputStream {
   _SocketInputStream(Socket socket) : _socket = socket {
     if (_socket._closed) _closed = true;
     _socket.onClosed = _onClosed;
@@ skipping 40 matching lines @@
 
   void _onClosed() {
     _closed = true;
     if (_clientCloseHandler != null) {
       _clientCloseHandler();
     }
   }
 
   bool _onSocketError(e) {
     close();
+    if (_error) return true;
     if (_onError != null) {
       _onError(e);
       return true;
     } else {
       return false;
     }
   }
 
   Socket _socket;
   bool _closed = false;
@@ skipping 51 matching lines @@
     if (_onNoPendingWrites != null) {
       _socket._onWrite = _onWrite;
     }
   }
 
   void set onClosed(void callback()) {
     _onClosed = callback;
   }
 
   bool _write(List<int> buffer, int offset, int len, bool copyBuffer) {
-    if (_closing || _closed) throw new StreamException("Stream closed");
+    if (_closing || _closed) {
+      if (_error) return false;
+      _error = true;
+      var e = new StreamException.streamClosed();
+      if (_onError != null) {
+        _onError(e);
+        return false;
+      } else {
+        throw e;
+      }
+    }
     int bytesWritten = 0;
     if (_pendingWrites.isEmpty) {
       // If nothing is buffered write as much as possible and buffer
       // the rest.
-      bytesWritten = _socket.writeList(buffer, offset, len);
-      if (bytesWritten == len) return true;
+      try {
+        bytesWritten = _socket.writeList(buffer, offset, len);
+        if (bytesWritten == len) return true;
+      } catch (e) {
+        if (_error) return false;
+        _error = true;
+        if (_onError != null) {
+          _onError(e);
+          return false;
+        } else {
+          throw e;
+        }
+      }
     }
 
     // Place remaining data on the pending writes queue.
     int notWrittenOffset = offset + bytesWritten;
     if (copyBuffer) {
       List<int> newBuffer =
           buffer.getRange(notWrittenOffset, len - bytesWritten);
       _pendingWrites.add(newBuffer);
     } else {
       assert(offset + len == buffer.length);
       _pendingWrites.add(buffer, notWrittenOffset);
     }
     _socket._onWrite = _onWrite;
     return false;
   }
 
   void _onWrite() {
     // Write as much buffered data to the socket as possible.
     while (!_pendingWrites.isEmpty) {
       List<int> buffer = _pendingWrites.first;
       int offset = _pendingWrites.index;
       int bytesToWrite = buffer.length - offset;
       int bytesWritten;
       try {
         bytesWritten = _socket.writeList(buffer, offset, bytesToWrite);
       } catch (e) {
         _pendingWrites.clear();
-        _onSocketError(e);
+        if (_onError != null) _onError(e);
         return;
       }
       _pendingWrites.removeBytes(bytesWritten);
       if (bytesWritten < bytesToWrite) {
         _socket._onWrite = _onWrite;
         return;
       }
     }
 
     // All buffered data was written.
@@ skipping 22 matching lines @@
       throw e;
     }
   }
 
   Socket _socket;
   _BufferList _pendingWrites;
   Function _onNoPendingWrites;
   Function _onClosed;
   bool _closing = false;
   bool _closed = false;
+  bool _error = false;
 }