Protect the use of session_media

src/audio/audiortp.cpp

@@ -190,6 +190,9 @@ AudioRtpRTX::initAudioRtpSession (void)
     try {
         if (_ca == 0) { return; }
         _audiocodec = _ca->getLocalSDP()->get_session_media ();
+
+        if (_audiocodec == NULL) { return; }
+
         _codecSampleRate = _audiocodec->getClockRate(); 
 
         ost::InetHostAddress remote_ip(_ca->getLocalSDP()->get_remote_ip().c_str());

src/sdp.cpp

@@ -303,12 +303,18 @@ AudioCodec* Sdp::get_session_media( void ){
 
     int nb_media;
     int nb_codec;
+    AudioCodec *codec = NULL;
 
     nb_media = _session_media.size();
+    if (nb_media > 0) {
         nb_codec = _session_media[0]->get_media_codec_list().size();
-
-    return _session_media[0]->get_media_codec_list()[0];
+        if (nb_codec > 0) {
+            codec = _session_media[0]->get_media_codec_list()[0];
+        }
     }
+    return codec;
+}
+
 
 
 void Sdp::toString (void) {

src/sipvoiplink.cpp

@@ -846,11 +846,17 @@ SIPVoIPLink::isRecording(const CallID& id)
 SIPVoIPLink::getCurrentCodecName()
 {
 
-    SIPCall *call = getSIPCall(Manager::instance().getCurrentCallId());  
+    SIPCall *call;
+    AudioCodec *ac;
+    std::string name = "";
+    
+    call = getSIPCall(Manager::instance().getCurrentCallId());  
+    ac = call->getLocalSDP()->get_session_media();
 
-    AudioCodec *ac = call->getLocalSDP()->get_session_media();
+    if (ac)
+        name = ac->getCodecName();
 
-    return ac->getCodecName();
+    return name;
 }
 
     bool