Bugfix: Exclude packet with zero SSRC in GetRtxOsnLoggingStatus

Since 0 is the sentinel value for "unset rtx_ssrc", we should exclude it.

Bug: b/423646186
Change-Id: Iff6e8985bdd20b8c1889a375b0023670a0162f3d
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/481300
Auto-Submit: Rasmus Brandt <brandtr@webrtc.org>
Commit-Queue: Åsa Persson <asapersson@webrtc.org>
Commit-Queue: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47996}

video/timing/simulator/log_classifiers.cc

diff --git a/video/timing/simulator/log_classifiers.cc b/video/timing/simulator/log_classifiers.cc
index 4621d87..5544a41 100644
--- a/video/timing/simulator/log_classifiers.cc
+++ b/video/timing/simulator/log_classifiers.cc
@@ -39,6 +39,10 @@
     if (!parsed_log.incoming_rtx_ssrcs().contains(stream.ssrc)) {
       continue;
     }
+    // Skip "unset rtx_ssrc" streams.
+    if (stream.ssrc == 0) {
+      continue;
+    }
     // Check all packets for this video RTX stream.
     for (const LoggedRtpPacketIncoming& incoming_packet :
          stream.incoming_packets) {

video/timing/simulator/log_classifiers_unittest.cc

diff --git a/video/timing/simulator/log_classifiers_unittest.cc b/video/timing/simulator/log_classifiers_unittest.cc
index 8312b58..36ce4d5 100644
--- a/video/timing/simulator/log_classifiers_unittest.cc
+++ b/video/timing/simulator/log_classifiers_unittest.cc
@@ -87,5 +87,14 @@
             RtxOsnLoggingStatus::kAllRtxOsnLogged);
 }
 
+TEST(GetRtxOsnLoggingStatusTest, RtxSsrc0IsExcluded) {
+  ParsedRtcEventLogBuilder builder;
+  builder.LogVideoRecvConfig(kSsrc, /*rtx_ssrc=*/0);
+  builder.LogRtpPacketIncoming(/*ssrc=*/0, std::nullopt);
+  std::unique_ptr<ParsedRtcEventLog> parsed_log = builder.Build();
+
+  EXPECT_EQ(GetRtxOsnLoggingStatus(*parsed_log), std::nullopt);
+}
+
 }  // namespace
 }  // namespace webrtc::video_timing_simulator