Fix a QUIC bug where a packet could remain in the UnackedPacketMap

net/quic/quic_sent_packet_manager.cc

 // Copyright 2013 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_sent_packet_manager.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/stl_util.h"
@@ skipping 154 matching lines @@
   while (it != unacked_packets_.end()) {
     QuicPacketSequenceNumber sequence_number = it->first;
     if (sequence_number > received_info.largest_observed) {
       // These packets are still in flight.
       break;
     }
 
     if (IsAwaitingPacket(received_info, sequence_number)) {
       // Remove any packets not being tracked by the send algorithm, allowing
       // the high water mark to be raised if necessary.
-      if (QuicUnackedPacketMap::IsSentAndNotPending(it->second)) {
+      if (QuicUnackedPacketMap::IsForRttOnly(it->second)) {
         it = MarkPacketHandled(sequence_number, delta_largest_observed);
       } else {
         // Consider it multiple nacks when there is a gap between the missing
         // packet and the largest observed, since the purpose of a nack
         // threshold is to tolerate re-ordering.  This handles both StretchAcks
         // and Forward Acks.
         // The nack count only increases when the largest observed increases.
         size_t min_nacks = received_info.largest_observed - sequence_number;
         // Truncated acks can nack the largest observed, so use a min of 1.
         if (min_nacks == 0) {
@@ skipping 68 matching lines @@
   for (QuicUnackedPacketMap::const_iterator it = unacked_packets_.begin();
        it != unacked_packets_.end(); ++it) {
     const RetransmittableFrames* frames =
         it->second.retransmittable_frames;
     if (frames != NULL && frames->encryption_level() == ENCRYPTION_NONE) {
       // Once you're forward secure, no unencrypted packets will be sent, crypto
       // or otherwise. Unencrypted packets are neutered and abandoned, to ensure
       // they are not retransmitted or considered lost from a congestion control
       // perspective.
       pending_retransmissions_.erase(it->first);
-      // TODO(ianswett): This may cause packets to linger forever in the
-      // UnackedPacketMap.
       unacked_packets_.NeuterPacket(it->first);
       unacked_packets_.SetNotPending(it->first);
     }
   }
 }
 
 void QuicSentPacketManager::MarkForRetransmission(
     QuicPacketSequenceNumber sequence_number,
     TransmissionType transmission_type) {
   const TransmissionInfo& transmission_info =
@@ skipping 490 matching lines @@
     return;
   }
 
   using_pacing_ = true;
   send_algorithm_.reset(
       new PacingSender(send_algorithm_.release(),
                        QuicTime::Delta::FromMicroseconds(1)));
 }
 
 }  // namespace net