Change the default for the len argument to writeFrom on OutputStream

runtime/bin/socket_stream.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 SocketInputStream implements InputStream {
   SocketInputStream(Socket socket) {
     _socket = socket;
   }
 
   List<int> read([int len]) {
@@ skipping 89 matching lines @@
 }
 
 
 class SocketOutputStream implements OutputStream {
   SocketOutputStream(Socket socket)
       : _socket = socket, _pendingWrites = new _BufferList2() {
     _socket.writeHandler = _writeHandler;
     _socket.errorHandler = _errorHandler;
   }
 
-  bool write(List<int> buffer) {
-    return _write(buffer, 0, buffer.length, false);
+    bool write(List<int> buffer, [bool copyBuffer = true]) {
+    return _write(buffer, 0, buffer.length, copyBuffer);
   }
 
   bool writeFrom(List<int> buffer, [int offset = 0, int len]) {
-    return _write(buffer, offset, (len == null) ? buffer.length : len, true);
+    return _write(
+        buffer, offset, (len == null) ? buffer.length - offset : len, true);
   }
 
   void close() {
     if (!_pendingWrites.isEmpty()) {
       // Mark the socket for close when all data is written.
       _closing = true;
       _socket.writeHandler = _writeHandler;
     } else {
       // Close the socket for writing.
       _socket._closeWrite();
@@ skipping 16 matching lines @@
   void set closeHandler(void callback()) {
     _socket.closeHandler = callback;
   }
 
   void set errorHandler(void callback()) {
     _streamErrorHandler = callback;
   }
 
   bool _write(List<int> buffer, int offset, int len, bool copyBuffer) {
     if (_closing || _closed) throw new StreamException("Stream closed");
-    if (len == null) len = buffer.length;
     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;
     }
 
     // Place remaining data on the pending writes queue.
+    int notWrittenOffset = offset + bytesWritten;
     if (copyBuffer) {
       List<int> newBuffer =
-          buffer.getRange(offset + bytesWritten, buffer.length);
+          buffer.getRange(notWrittenOffset, len - bytesWritten);
       _pendingWrites.add(newBuffer);
     } else {
-      _pendingWrites.add(buffer, bytesWritten);
+      assert(offset + len = buffer.length);
+      _pendingWrites.add(buffer, notWrittenOffset);
     }
   }
 
   void _writeHandler() {
     // 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 = _socket.writeList(buffer, offset, bytesToWrite);
@@ skipping 18 matching lines @@
     if (_streamErrorHandler != null) _streamErrorHandler();
   }
 
   Socket _socket;
   _BufferList2 _pendingWrites;
   var _noPendingWriteHandler;
   var _streamErrorHandler;
   bool _closing = false;
   bool _closed = false;
 }