cleanup

Signal/src/call/CallService.swift

@@ -466,6 +466,9 @@ fileprivate let timeoutSeconds = 60
         terminateCall()
     }
 
+    /**
+     * Answer call by call `localId`, used by notification actions which can't serialize a call object.
+     */
     public func handleAnswerCall(localId: UUID) {
         // TODO #function is called from objc, how to access swift defiend dispatch queue (OS_dispatch_queue)
         //assertOnSignalingQueue()
@@ -529,6 +532,10 @@ fileprivate let timeoutSeconds = 60
         handleConnectedCall(call)
     }
 
+    /**
+     * Called by initiator when recipient answers the call.
+     * Called by recipient upon answering the call.
+     */
     func handleConnectedCall(_ call: SignalCall) {
         Logger.debug("\(TAG) in \(#function)")
         assertOnSignalingQueue()
@@ -827,7 +834,7 @@ fileprivate let timeoutSeconds = 60
                 self.handleIceConnected()
             case .failed:
                 Logger.warn("\(self.TAG) RTCIceConnection failed.")
-                guard let thread = self.thread else {
+                guard self.thread != nil else {
                     Logger.error("\(self.TAG) refusing to hangup for failed IceConnection because there is no current thread")
                     return
                 }

Signal/src/call/PeerConnectionClient.swift

@@ -80,8 +80,11 @@ class PeerConnectionClient: NSObject, SignalCallAudioManager {
     // MARK: Video
 
     fileprivate func createVideoSender() {
+        Logger.debug("\(TAG) in \(#function)")
+        assert(self.videoSender == nil, "\(#function) should only be called once.")
+
         guard !Platform.isSimulator else {
-            Logger.warn("\(TAG) Refusing to create local video track on simulator.")
+            Logger.warn("\(TAG) Refusing to create local video track on simulator which has no capture device.")
             return
         }
 
@@ -119,6 +122,9 @@ class PeerConnectionClient: NSObject, SignalCallAudioManager {
     // MARK: Audio
 
     fileprivate func createAudioSender() {
+        Logger.debug("\(TAG) in \(#function)")
+        assert(self.audioSender == nil, "\(#function) should only be called once.")
+
         let audioSource = factory.audioSource(with: self.audioConstraints)
 
         let audioTrack = factory.audioTrack(with: audioSource, trackId: Identifiers.audioTrack.rawValue)