Add the ability to run tests with several sets of VM flags

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;
     _buffer = null;
   }
 
@@ skipping 79 matching lines @@
     } else {
       buffer = new List<int>(appendingBufferSpace);
     }
     buffer.copyFrom(newBuffer, 0, newDataStart, appendingBufferSpace);
     return buffer;
   }
 
   void readUntil(List<int> pattern, void callback(List<int> resultBuffer)) {
     void doRead() {
       List<int> newBuffer;
-      if (_buffer != null) {
-        newBuffer = _buffer;
-      } else {
-        int size = _socket.available();
-        List<int> buffer = new List<int>(size);
-        int result = _socket.readList(buffer, 0, size);
+      int available = _socket.available();
+      if (available > 0) {
+        List<int> buffer = new List<int>(available);
+        int result = _socket.readList(buffer, 0, buffer.length);
         if (result > 0) {
           // TODO(hpayer): Avoid copying of data before pattern matching.
           newBuffer = _getBufferedData(buffer, result);
         }
+      } else if (_buffer != null) {
+        newBuffer = _buffer;
+      } else {
+        _socket.setDataHandler(doRead);
+        return;
       }
 
       int index = _matchPattern(newBuffer, pattern, 0);
       // If pattern was found return the data including pattern and store the
       // remainder in the buffer.
       if (index != -1) {
         int finalBufferSize = index + pattern.length;
         List<int> finalBuffer = new List<int>(finalBufferSize);
         finalBuffer.copyFrom(newBuffer, 0, 0, finalBufferSize);
         if (finalBufferSize < newBuffer.length) {
@@ skipping 53 matching lines @@
 
     if (bytesWritten == len) {
       return true;
     }
     _socket.setWriteHandler(finishWrite);
     return false;
   }
 
   Socket _socket;
 }