Fix for scenario where m-line is revived after being set to port 0.

talk/app/webrtc/peerconnection.cc

 /*
  * libjingle
  * Copyright 2012 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 931 matching lines @@
   if (session_->data_channel_type() == cricket::DCT_SCTP &&
       session_->GetSslRole(&role)) {
     AllocateSctpSids(role);
   }
 
   // Update state and SSRC of local MediaStreams and DataChannels based on the
   // local session description.
   const cricket::ContentInfo* audio_content =
       GetFirstAudioContent(desc->description());
   if (audio_content) {
-    const cricket::AudioContentDescription* audio_desc =
-        static_cast<const cricket::AudioContentDescription*>(
-            audio_content->description);
-    UpdateLocalTracks(audio_desc->streams(), audio_desc->type());
+    if (audio_content->rejected) {
+      RemoveTracks(cricket::MEDIA_TYPE_AUDIO);
+    } else {
+      const cricket::AudioContentDescription* audio_desc =
+          static_cast<const cricket::AudioContentDescription*>(
+              audio_content->description);
+      UpdateLocalTracks(audio_desc->streams(), audio_desc->type());
+    }
   }
 
   const cricket::ContentInfo* video_content =
       GetFirstVideoContent(desc->description());
   if (video_content) {
-    const cricket::VideoContentDescription* video_desc =
-        static_cast<const cricket::VideoContentDescription*>(
-            video_content->description);
-    UpdateLocalTracks(video_desc->streams(), video_desc->type());
+    if (video_content->rejected) {
+      RemoveTracks(cricket::MEDIA_TYPE_VIDEO);
+    } else {
+      const cricket::VideoContentDescription* video_desc =
+          static_cast<const cricket::VideoContentDescription*>(
+              video_content->description);
+      UpdateLocalTracks(video_desc->streams(), video_desc->type());
+    }
   }
 
   const cricket::ContentInfo* data_content =
       GetFirstDataContent(desc->description());
   if (data_content) {
     const cricket::DataContentDescription* data_desc =
         static_cast<const cricket::DataContentDescription*>(
             data_content->description);
     if (rtc::starts_with(data_desc->protocol().data(),
                          cricket::kMediaProtocolRtpPrefix)) {
@@ skipping 41 matching lines @@
   const cricket::SessionDescription* remote_desc = desc->description();
 
   // We wait to signal new streams until we finish processing the description,
   // since only at that point will new streams have all their tracks.
   rtc::scoped_refptr<StreamCollection> new_streams(StreamCollection::Create());
 
   // Find all audio rtp streams and create corresponding remote AudioTracks
   // and MediaStreams.
   const cricket::ContentInfo* audio_content = GetFirstAudioContent(remote_desc);
   if (audio_content) {
-    const cricket::AudioContentDescription* desc =
-        static_cast<const cricket::AudioContentDescription*>(
-            audio_content->description);
-    UpdateRemoteStreamsList(GetActiveStreams(desc), desc->type(), new_streams);
-    remote_info_.default_audio_track_needed =
-        !remote_desc->msid_supported() && desc->streams().empty() &&
-        MediaContentDirectionHasSend(desc->direction());
+    if (audio_content->rejected) {
+      RemoveTracks(cricket::MEDIA_TYPE_AUDIO);
+    } else {
+      const cricket::AudioContentDescription* desc =
+          static_cast<const cricket::AudioContentDescription*>(
+              audio_content->description);
+      UpdateRemoteStreamsList(GetActiveStreams(desc), desc->type(),
+                              new_streams);
+      remote_info_.default_audio_track_needed =
+          !remote_desc->msid_supported() && desc->streams().empty() &&
+          MediaContentDirectionHasSend(desc->direction());
+    }
   }
 
   // Find all video rtp streams and create corresponding remote VideoTracks
   // and MediaStreams.
   const cricket::ContentInfo* video_content = GetFirstVideoContent(remote_desc);
   if (video_content) {
-    const cricket::VideoContentDescription* desc =
-        static_cast<const cricket::VideoContentDescription*>(
-            video_content->description);
-    UpdateRemoteStreamsList(GetActiveStreams(desc), desc->type(), new_streams);
-    remote_info_.default_video_track_needed =
-        !remote_desc->msid_supported() && desc->streams().empty() &&
-        MediaContentDirectionHasSend(desc->direction());
+    if (video_content->rejected) {
+      RemoveTracks(cricket::MEDIA_TYPE_VIDEO);
+    } else {
+      const cricket::VideoContentDescription* desc =
+          static_cast<const cricket::VideoContentDescription*>(
+              video_content->description);
+      UpdateRemoteStreamsList(GetActiveStreams(desc), desc->type(),
+                              new_streams);
+      remote_info_.default_video_track_needed =
+          !remote_desc->msid_supported() && desc->streams().empty() &&
+          MediaContentDirectionHasSend(desc->direction());
+    }
   }
 
   // Update the DataChannels with the information from the remote peer.
   const cricket::ContentInfo* data_content = GetFirstDataContent(remote_desc);
   if (data_content) {
     const cricket::DataContentDescription* desc =
         static_cast<const cricket::DataContentDescription*>(
             data_content->description);
     if (rtc::starts_with(desc->protocol().data(),
                          cricket::kMediaProtocolRtpPrefix)) {
@@ skipping 370 matching lines @@
 
   // RTP data channel is handled in MediaSessionOptions::AddStream. SCTP streams
   // are not signaled in the SDP so does not go through that path and must be
   // handled here.
   if (session_->data_channel_type() == cricket::DCT_SCTP) {
     session_options->data_channel_type = cricket::DCT_SCTP;
   }
   return true;
 }
 
+void PeerConnection::RemoveTracks(cricket::MediaType media_type) {
+  UpdateLocalTracks(std::vector<cricket::StreamParams>(), media_type);
+  UpdateRemoteStreamsList(std::vector<cricket::StreamParams>(), media_type,
+                          nullptr);
+}
+
 void PeerConnection::UpdateRemoteStreamsList(
     const cricket::StreamParamsVec& streams,
     cricket::MediaType media_type,
     StreamCollection* new_streams) {
   TrackInfos* current_tracks = GetRemoteTracks(media_type);
 
   // Find removed tracks. I.e., tracks where the track id or ssrc don't match
   // the
   // new StreamParam.
   auto track_it = current_tracks->begin();
@@ skipping 520 matching lines @@
 DataChannel* PeerConnection::FindDataChannelBySid(int sid) const {
   for (const auto& channel : sctp_data_channels_) {
     if (channel->id() == sid) {
       return channel;
     }
   }
   return nullptr;
 }
 
 }  // namespace webrtc