Fix memory leak in MacOS process handling.

runtime/bin/socket_impl.dart

 // Copyright (c) 2011, 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.
 
 
 class _SocketBase {
   // Bit flags used when communicating between the eventhandler and
   // dart code. The EVENT flags are used to indicate events of
   // interest when sending a message from dart code to the
   // eventhandler. When receiving a message from the eventhandler the
@@ skipping 280 matching lines @@
         throw new IndexOutOfRangeException(offset);
       }
       if (bytes < 0) {
         throw new IndexOutOfRangeException(bytes);
       }
       if ((offset + bytes) > buffer.length) {
         throw new IndexOutOfRangeException(offset + bytes);
       }
       int result = _readList(buffer, offset, bytes);
       if (result < 0) {
-        throw new SocketIOException("Error: readList failed");
+        _reportError();
       }
       return result;
     }
     throw new
         SocketIOException("Error: readList failed - invalid socket handle");
   }
 
   int _readList(List<int> buffer, int offset, int bytes)
       native "Socket_ReadList";
 
   int writeList(List<int> buffer, int offset, int bytes) {
     if (_id >= 0) {
       if (bytes == 0) {
         return 0;
       }
       if (offset < 0) {
         throw new IndexOutOfRangeException(offset);
       }
       if (bytes < 0) {
         throw new IndexOutOfRangeException(bytes);
       }
       if ((offset + bytes) > buffer.length) {
         throw new IndexOutOfRangeException(offset + bytes);
       }
-      return _writeList(buffer, offset, bytes);
+      var bytes_written = _writeList(buffer, offset, bytes);
+      if (bytes_written < 0) {
+        // If writing fails we return 0 as the number of bytes and
+        // report the error on the error handler.
+        bytes_written = 0;
+        _reportError();
+      }
+      return bytes_written;
     }
     throw new
         SocketIOException("Error: writeList failed - invalid socket handle");
   }
 
   int _writeList(List<int> buffer, int offset, int bytes)
       native "Socket_WriteList";
 
+  void _reportError() {
+    // For all errors we close the socket, call the error handler and
+    // disable further calls of the error handler.
+    close();
+    var errorHandler = _handlerMap[_ERROR_EVENT];
+    if (errorHandler != null) {
+      errorHandler();
+      _setHandler(_ERROR_EVENT, null);
+    }
+  }
+
   bool _createConnect(String host, int port) native "Socket_CreateConnect";
 
   void set writeHandler(void callback()) {
     _setHandler(_OUT_EVENT, callback);
   }
 
   void set connectHandler(void callback()) {
     _setHandler(_OUT_EVENT, callback);
   }
 
@@ skipping 22 matching lines @@
     return _outputStream;
   }
 
   bool _closedRead = false;
   bool _closedWrite = false;
   bool _pipe = false;
   SocketInputStream _inputStream;
   SocketOutputStream _outputStream;
 }