Fix read loop in SocketStream.

net/socket_stream/socket_stream.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // TODO(ukai): code is similar with http_network_transaction.cc.  We should
 //   think about ways to share code, if possible.
 
 #include "net/socket_stream/socket_stream.h"
 
 #include <string>
@@ skipping 560 matching lines @@
     return result;
   }
   if (!socket_.get() || !socket_->IsConnected()) {
     Finish();
     return ERR_CONNECTION_CLOSED;
   }
 
   next_state_ = STATE_READ_WRITE;
 
   if (!read_buf_) {
+    // No read pending.
     read_buf_ = new IOBuffer(kReadBufferSize);
     result = socket_->Read(read_buf_, kReadBufferSize, &read_callback_);
     if (result > 0) {
       DidReceiveData(result);
-      result = OK;
+      return OK;
     } else if (result == 0) {
       // 0 indicates end-of-file, so socket was closed.
       Finish();
       return ERR_CONNECTION_CLOSED;
     }
+    // If read is pending, try write as well.
+    // Otherwise, return the result and do next loop.
+    if (result != ERR_IO_PENDING)
+      return result;
   }
+  // Read is pending.
+  DCHECK(read_buf_);
+
   if (write_buf_ && !current_write_buf_) {
+    // No write pending.
     current_write_buf_ = new DrainableIOBuffer(write_buf_, write_buf_size_);
     current_write_buf_->SetOffset(write_buf_offset_);
     result = socket_->Write(current_write_buf_,
                             current_write_buf_->BytesRemaining(),
                             &write_callback_);
     if (result > 0) {
       DidSendData(result);
-      result = OK;
+      return OK;
     }
+    return result;
   }
 
-  // We arrived here when Write is performed and finished.
-  if (result == OK)
-    return ERR_IO_PENDING;
-  return result;
+  // We arrived here when both operation is pending.
+  return ERR_IO_PENDING;
 }
 
 int SocketStream::HandleCertificateError(int result) {
   // TODO(ukai): handle cert error properly.
   switch (result) {
     case ERR_CERT_COMMON_NAME_INVALID:
     case ERR_CERT_DATE_INVALID:
     case ERR_CERT_AUTHORITY_INVALID:
       result = OK;
       break;
     default:
       break;
   }
   return result;
 }
 
 bool SocketStream::is_secure() const {
   return url_.SchemeIs("wss");
 }
 
 SSLConfigService* SocketStream::ssl_config_service() const {
   return context_->ssl_config_service();
 }
 
 ProxyService* SocketStream::proxy_service() const {
   return context_->proxy_service();
 }
 
 }  // namespace net