relnote: Protect against a QUIC crash bug but logging a DFATAL and

net/quic/quic_packet_creator.cc

 // Copyright (c) 2012 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.
 
 #include "net/quic/quic_packet_creator.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
@@ skipping 445 matching lines @@
   // packet sizes are properly used.
   scoped_ptr<char[]> large_buffer;
   if (packet_size_ <= kMaxPacketSize) {
     packet.reset(
         framer_->BuildDataPacket(header, queued_frames_, buffer, packet_size_));
   } else {
     large_buffer.reset(new char[packet_size_]);
     packet.reset(framer_->BuildDataPacket(header, queued_frames_,
                                           large_buffer.get(), packet_size_));
   }
-  LOG_IF(DFATAL, packet == nullptr) << "Failed to serialize "
-                                    << queued_frames_.size() << " frames.";
+  if (packet == nullptr) {
+    LOG(DFATAL) << "Failed to serialize " << queued_frames_.size()
+                << " frames.";
+    return NoPacket();
+  }
 
   OnBuiltFecProtectedPayload(header, packet->FecProtectedData());
 
   // Because of possible truncation, we can't be confident that our
   // packet size calculation worked correctly.
   if (!possibly_truncated_by_length) {
     DCHECK_EQ(packet_size_, packet->length());
   }
   // Immediately encrypt the packet, to ensure we don't encrypt the same packet
   // sequence number multiple times.
@@ skipping 147 matching lines @@
     // Don't pad full packets.
     return;
   }
 
   QuicPaddingFrame padding;
   bool success = AddFrame(QuicFrame(&padding), false, false, nullptr);
   DCHECK(success);
 }
 
 }  // namespace net