Only generate one CNAME per PeerConnection.

webrtc/api/peerconnectioninterface_unittest.cc

 /*
  *  Copyright 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 916 matching lines @@
   }
 
   void AddVideoTrack(const std::string& track_id,
                      MediaStreamInterface* stream) {
     rtc::scoped_refptr<webrtc::VideoTrackInterface> video_track(
         webrtc::VideoTrack::Create(track_id,
                                    webrtc::FakeVideoTrackSource::Create()));
     ASSERT_TRUE(stream->AddTrack(video_track));
   }
 
+  rtc::scoped_ptr<SessionDescriptionInterface> CreateOfferWithOneAudioStream() {
+    CreatePeerConnection();
+    AddVoiceStream(kStreamLabel1);
+    rtc::scoped_ptr<SessionDescriptionInterface> offer;
+    EXPECT_TRUE(DoCreateOffer(&offer, nullptr));
+    return offer;
+  }
+
+  rtc::scoped_ptr<SessionDescriptionInterface>
+  CreateAnswerWithOneAudioStream() {
+    rtc::scoped_ptr<SessionDescriptionInterface> offer =
+        CreateOfferWithOneAudioStream();
+    EXPECT_TRUE(DoSetRemoteDescription(offer.release()));
+    rtc::scoped_ptr<SessionDescriptionInterface> answer;
+    EXPECT_TRUE(DoCreateAnswer(&answer, nullptr));
+    return answer;
+  }
+
+  const std::string& GetFirstAudioStreamCname(
+      const SessionDescriptionInterface* desc) {
+    const cricket::ContentInfo* audio_content =
+        cricket::GetFirstAudioContent(desc->description());
+    const cricket::AudioContentDescription* audio_desc =
+        static_cast<const cricket::AudioContentDescription*>(
+            audio_content->description);
+    return audio_desc->streams()[0].cname;
+  }
+
   cricket::FakePortAllocator* port_allocator_ = nullptr;
   scoped_refptr<webrtc::PeerConnectionFactoryInterface> pc_factory_;
   scoped_refptr<PeerConnectionInterface> pc_;
   MockPeerConnectionObserver observer_;
   rtc::scoped_refptr<StreamCollection> reference_collection_;
 };
 
+// Generate different CNAMEs when PeerConnections are created.
+// The CNAMEs are expected to be generated randomly. It is possible
+// that the test fails, though the possibility is very low.
+TEST_F(PeerConnectionInterfaceTest, CnameGenerationInOffer) {
+  rtc::scoped_ptr<SessionDescriptionInterface> offer1 =
+      CreateOfferWithOneAudioStream();
+  rtc::scoped_ptr<SessionDescriptionInterface> offer2 =
+      CreateOfferWithOneAudioStream();
+  EXPECT_NE(GetFirstAudioStreamCname(offer1.get()),
+            GetFirstAudioStreamCname(offer2.get()));
+}
+
+TEST_F(PeerConnectionInterfaceTest, CnameGenerationInAnswer) {
+  rtc::scoped_ptr<SessionDescriptionInterface> answer1 =
+      CreateAnswerWithOneAudioStream();
+  rtc::scoped_ptr<SessionDescriptionInterface> answer2 =
+      CreateAnswerWithOneAudioStream();
+  EXPECT_NE(GetFirstAudioStreamCname(answer1.get()),
+            GetFirstAudioStreamCname(answer2.get()));
+}
+
 TEST_F(PeerConnectionInterfaceTest,
        CreatePeerConnectionWithDifferentConfigurations) {
   CreatePeerConnectionWithDifferentConfigurations();
 }
 
 TEST_F(PeerConnectionInterfaceTest, AddStreams) {
   CreatePeerConnection();
   AddVideoStream(kStreamLabel1);
   AddVoiceStream(kStreamLabel2);
   ASSERT_EQ(2u, pc_->local_streams()->count());
@@ skipping 1707 matching lines @@
   FakeConstraints updated_answer_c;
   answer_c.SetMandatoryReceiveAudio(false);
   answer_c.SetMandatoryReceiveVideo(false);
 
   cricket::MediaSessionOptions updated_answer_options;
   EXPECT_TRUE(
       ParseConstraintsForAnswer(&updated_answer_c, &updated_answer_options));
   EXPECT_TRUE(updated_answer_options.has_audio());
   EXPECT_TRUE(updated_answer_options.has_video());
 }