Make sure rid has a matching ssrc when requesting keyframe.

Bug: b/510386551
Change-Id: Ic1a6606d987dc2ff3dced041235317bc7436972b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/484940
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Auto-Submit: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#48072}

media/engine/webrtc_video_engine.cc

diff --git a/media/engine/webrtc_video_engine.cc b/media/engine/webrtc_video_engine.cc
index d952029..f813f18 100644
--- a/media/engine/webrtc_video_engine.cc
+++ b/media/engine/webrtc_video_engine.cc
@@ -2734,6 +2734,9 @@
     // SVC is used instead of simulcast. Remove unnecessary SSRCs.
     if (config.rtp.ssrcs.size() > 1) {
       config.rtp.ssrcs.resize(1);
+      if (config.rtp.rids.size() > 1) {
+        config.rtp.rids.resize(1);
+      }
       if (config.rtp.rtx.ssrcs.size() > 1) {
         config.rtp.rtx.ssrcs.resize(1);
       }

video/video_send_stream_impl.cc

diff --git a/video/video_send_stream_impl.cc b/video/video_send_stream_impl.cc
index fda5f0b..827da4d 100644
--- a/video/video_send_stream_impl.cc
+++ b/video/video_send_stream_impl.cc
@@ -665,6 +665,10 @@
 void VideoSendStreamImpl::GenerateKeyFrame(
     const std::vector<std::string>& rids) {
   RTC_DCHECK_RUN_ON(&thread_checker_);
+  if (!video_stream_encoder_) {
+    return;
+  }
+
   // Map rids to layers. If rids is empty, generate a keyframe for all layers.
   std::vector<VideoFrameType> next_frames(config_.rtp.ssrcs.size(),
                                           VideoFrameType::kVideoFrameKey);
@@ -674,15 +678,16 @@
     for (const auto& rid : rids) {
       for (size_t i = 0; i < config_.rtp.rids.size(); i++) {
         if (config_.rtp.rids[i] == rid) {
-          next_frames[i] = VideoFrameType::kVideoFrameKey;
+          if (i < next_frames.size()) {
+            next_frames[i] = VideoFrameType::kVideoFrameKey;
+          }
           break;
         }
       }
     }
   }
-  if (video_stream_encoder_) {
-    video_stream_encoder_->SendKeyFrame(next_frames);
-  }
+
+  video_stream_encoder_->SendKeyFrame(next_frames);
 }
 
 void VideoSendStreamImpl::DeliverRtcp(std::span<const uint8_t> packet) {

video/video_send_stream_impl_unittest.cc

diff --git a/video/video_send_stream_impl_unittest.cc b/video/video_send_stream_impl_unittest.cc
index 6cbf89f..a3046f6 100644
--- a/video/video_send_stream_impl_unittest.cc
+++ b/video/video_send_stream_impl_unittest.cc
@@ -1507,5 +1507,17 @@
   vss_impl->Stop();
 }
 
+TEST_F(VideoSendStreamImplTest, GenerateKeyFrameWithMismatchedRids) {
+  // Multiple RIDs available for simulcast.
+  config_.rtp.rids = {"a", "b", "c"};
+  // Single encoder config (no simulcast, or potentially SVC).
+  auto vss_impl = CreateVideoSendStreamImpl(
+      TestVideoEncoderConfig(VideoEncoderConfig::ContentType::kRealtimeVideo));
+  vss_impl->Start();
+  // Generating a keyframe on a RID that is not available should be a noop.
+  vss_impl->GenerateKeyFrame({"c"});
+  vss_impl->Stop();
+}
+
 }  // namespace internal
 }  // namespace webrtc