1 files changed, 17 insertions, 12 deletions
diff --git a/media/webrtc/signaling/src/jsep/JsepTrack.cpp b/media/webrtc/signaling/src/jsep/JsepTrack.cpp
index 1b045d8ec7..cf5df96bf0 100644
--- a/media/webrtc/signaling/src/jsep/JsepTrack.cpp
+++ b/media/webrtc/signaling/src/jsep/JsepTrack.cpp
@@ -410,21 +410,26 @@ JsepTrack::NegotiateCodecs(
 
   // TODO(bug 814227): Remove this once we're ready to put multiple codecs in an
   // answer.  For now, remove all but the first codec unless the red codec
-  // exists, and then we include the others per RFC 5109, section 14.2.
-  // Note: now allows keeping the telephone-event codec, if it appears, as the
-  // last codec in the list.
+  // exists, in which case we include the others per RFC 5109, section 14.2.
   if (!codecs->empty() && !red) {
-    int newSize = dtmf ? 2 : 1;
-    for (size_t i = 1; i < codecs->size(); ++i) {
-      if (!dtmf || dtmf != (*codecs)[i]) {
-        delete (*codecs)[i];
-        (*codecs)[i] = nullptr;
+    std::vector<JsepCodecDescription*> codecsToKeep;
+
+    bool foundPreferredCodec = false;
+    for (auto codec: *codecs) {
+      if (codec == dtmf) {
+        codecsToKeep.push_back(codec);
+      // TODO: keep ulpfec when we enable it in Bug 875922
+      // } else if (codec == ulpfec) {
+      //   codecsToKeep.push_back(codec);
+      } else if (!foundPreferredCodec) {
+        codecsToKeep.insert(codecsToKeep.begin(), codec);
+        foundPreferredCodec = true;
+      } else {
+        delete codec;
       }
     }
-    if (dtmf) {
-      (*codecs)[newSize-1] = dtmf;
-    }
-    codecs->resize(newSize);
+
+    *codecs = codecsToKeep;
   }
 }