commit 522380ff734174faab694e1b67c9d20fffa8738e
author Philipp Hancke <phancke@microsoft.com> Tue May 09 07:41:03 2023
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue May 09 15:11:24 2023
tree 80fc785d9c701b11bbff42eb3ab927b43f9f5438
parent 8095d0288440866a2d425fedea725934cfa5512b

Attempt to recycle a stopped data m-line before creating a new one

which avoids an infinitely growing SDP if the remote end rejects
the datachannel section. This will reactivate the m-line even if
all datachannels are closed.

BUG=chromium:1442604

Change-Id: If60f93b406271163df692d96102baab701923602
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/304241
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Philipp Hancke <phancke@microsoft.com>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40029}

pc/peer_connection.cc

diff --git a/pc/peer_connection.cc b/pc/peer_connection.cc
index 0956d75..3f99c96 100644
--- a/pc/peer_connection.cc
+++ b/pc/peer_connection.cc
@@ -1420,9 +1420,10 @@
 
   rtc::scoped_refptr<DataChannelInterface> channel = ret.MoveValue();
 
-  // Trigger the onRenegotiationNeeded event for
-  // the first SCTP DataChannel.
-  if (first_datachannel) {
+  // Check the onRenegotiationNeeded event (with plan-b backward compat)
+  if (configuration_.sdp_semantics == SdpSemantics::kUnifiedPlan ||
+      (configuration_.sdp_semantics == SdpSemantics::kPlanB_DEPRECATED &&
+       first_datachannel)) {
     sdp_handler_->UpdateNegotiationNeeded();
   }
   NoteUsageEvent(UsageEvent::DATA_ADDED);