Do not crash on null stream in writing to bidirectional streams

net/quic/bidirectional_stream_quic_impl.cc

Index: net/quic/bidirectional_stream_quic_impl.cc
diff --git a/net/quic/bidirectional_stream_quic_impl.cc b/net/quic/bidirectional_stream_quic_impl.cc
index 3d1ae3cd4b31020e8638845d9e2ab2494acc7b27..ef5f9de7d03bdc3e11153c1d317326658c9ebd97 100644
--- a/net/quic/bidirectional_stream_quic_impl.cc
+++ b/net/quic/bidirectional_stream_quic_impl.cc
@@ -119,9 +119,16 @@ int BidirectionalStreamQuicImpl::ReadData(IOBuffer* buffer, int buffer_len) {
 void BidirectionalStreamQuicImpl::SendData(const scoped_refptr<IOBuffer>& data,
                                            int length,
                                            bool end_stream) {
-  DCHECK(stream_);
   DCHECK(length > 0 || (length == 0 && end_stream));
 
+  if (!stream_) {
+    LOG(ERROR) << "Trying to send data when stream has been destroyed.";

[mef, 2016/06/01 21:53:15]

when -> after

[xunjieli, 2016/06/01 23:08:22]

Done.

+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(&BidirectionalStreamQuicImpl::NotifyError,
+                              weak_factory_.GetWeakPtr(), ERR_UNEXPECTED));

[mef, 2016/06/01 21:53:15]

nit: Should say ERR_UNEXPECTED in CL description.

[xunjieli, 2016/06/01 23:08:22]

Done.

+    return;
+  }
+
   std::unique_ptr<QuicConnection::ScopedPacketBundler> bundler;
   if (!has_sent_headers_) {
     DCHECK(!send_request_headers_automatically_);
@@ -149,9 +156,16 @@ void BidirectionalStreamQuicImpl::SendvData(
     const std::vector<scoped_refptr<IOBuffer>>& buffers,
     const std::vector<int>& lengths,
     bool end_stream) {
-  DCHECK(stream_);
   DCHECK_EQ(buffers.size(), lengths.size());
 
+  if (!stream_) {
+    LOG(ERROR) << "Trying to send data when stream has been destroyed.";

[mef, 2016/06/01 21:53:15]

when -> after

[xunjieli, 2016/06/01 23:08:22]

Done.

+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(&BidirectionalStreamQuicImpl::NotifyError,
+                              weak_factory_.GetWeakPtr(), ERR_UNEXPECTED));
+    return;
+  }
+
   QuicConnection::ScopedPacketBundler bundler(
       session_->connection(), QuicConnection::SEND_ACK_IF_PENDING);
   if (!has_sent_headers_) {
@@ -233,12 +247,12 @@ void BidirectionalStreamQuicImpl::OnDataAvailable() {
 
 void BidirectionalStreamQuicImpl::OnClose(QuicErrorCode error) {
   DCHECK(stream_);
+
   if (error == QUIC_NO_ERROR &&
       stream_->stream_error() == QUIC_STREAM_NO_ERROR) {
     ResetStream();
     return;
   }
-  ResetStream();

[mef, 2016/06/01 21:53:15]

Why no longer ResetStream() here?

[xunjieli, 2016/06/01 23:08:22]

It is redundant. NotifyError will call ResetStream().

   NotifyError(was_handshake_confirmed_ ? ERR_QUIC_PROTOCOL_ERROR
                                        : ERR_QUIC_HANDSHAKE_FAILED);
 }