Bug 1421965: Avoid nullptr crash when conduits cannot be created. r=drno

MozReview-Commit-ID: AdWiIbpFP0Y

--HG--
extra : rebase_source : 5e2327f1ddf2249ba0f55c5dcbb4acdf49b65133

media/webrtc/signaling/src/peerconnection/PeerConnectionMedia.cpp

@@ -1148,6 +1148,10 @@ PeerConnectionMedia::AddTransceiver(
       aSendTrack,
       mCall.get());
 
+  if (!transceiver->IsValid()) {
+    return NS_ERROR_FAILURE;
+  }
+
   if (aSendTrack) {
     // implement checking for peerIdentity (where failure == black/silence)
     nsIDocument* doc = mParent->GetWindow()->GetExtantDoc();

media/webrtc/signaling/src/peerconnection/TransceiverImpl.cpp

@@ -56,6 +56,10 @@ TransceiverImpl::TransceiverImpl(
     InitAudio();
   }
 
+  if (!IsValid()) {
+    return;
+  }
+
   mConduit->SetPCHandle(mPCHandle);
 
   StartReceiveStream();
@@ -78,6 +82,14 @@ TransceiverImpl::InitAudio()
 {
   mConduit = AudioSessionConduit::Create();
 
+  if (!mConduit) {
+    MOZ_MTLOG(ML_ERROR, mPCHandle << "[" << mMid << "]: " << __FUNCTION__ <<
+                        ": Failed to create AudioSessionConduit");
+    // TODO(bug 1422897): We need a way to record this when it happens in the
+    // wild.
+    return;
+  }
+
   mReceivePipeline = new MediaPipelineReceiveAudio(
       mPCHandle,
       mMainThread.get(),
@@ -91,6 +103,14 @@ TransceiverImpl::InitVideo()
 {
   mConduit = VideoSessionConduit::Create(mCallWrapper);
 
+  if (!mConduit) {
+    MOZ_MTLOG(ML_ERROR, mPCHandle << "[" << mMid << "]: " << __FUNCTION__ <<
+                        ": Failed to create VideoSessionConduit");
+    // TODO(bug 1422897): We need a way to record this when it happens in the
+    // wild.
+    return;
+  }
+
   mReceivePipeline = new MediaPipelineReceiveVideo(
       mPCHandle,
       mMainThread.get(),

media/webrtc/signaling/src/peerconnection/TransceiverImpl.h

@@ -59,6 +59,11 @@ public:
                   dom::MediaStreamTrack* aSendTrack,
                   WebRtcCallWrapper* aCallWrapper);
 
+  bool IsValid() const
+  {
+    return !!mConduit;
+  }
+
   nsresult UpdateSendTrack(dom::MediaStreamTrack* aSendTrack);
 
   nsresult UpdateSinkIdentity(dom::MediaStreamTrack* aTrack,