MSRP: lift leaveNow for talker complement to reduce code duplication

Author: lhoward

Sources/MRP/Applications/MSRP/MSRPApplication.swift

@@ -906,12 +906,14 @@ extension MSRPApplication {
         accumulatedLatency += 500 // clause 35.2.2.8.6, 500ns default
       }
 
+      let complementToRemove: MSRPAttributeType =
+        declarationType == .talkerAdvertise ? .talkerFailed : .talkerAdvertise
+      try await participant.leaveNow { attributeType, _, attributeValue in
+        attributeType == complementToRemove.rawValue &&
+          (attributeValue as! MSRPStreamIDRepresentable).streamID == talkerValue.streamID
+      }
+
       if declarationType == .talkerAdvertise {
-        // Leave any existing talkerFailed before joining talkerAdvertise
-        try await participant.leaveNow { attributeType, _, attributeValue in
-          attributeType == MSRPAttributeType.talkerFailed.rawValue &&
-            (attributeValue as! MSRPStreamIDRepresentable).streamID == talkerValue.streamID
-        }
         do {
           try await _canBridgeTalker(
             participant: participant,
@@ -970,11 +972,6 @@ extension MSRPApplication {
         }
       } else {
         precondition(declarationType == .talkerFailed)
-        // Leave any existing talkerAdvertise before joining talkerFailed
-        try await participant.leaveNow { attributeType, _, attributeValue in
-          attributeType == MSRPAttributeType.talkerAdvertise.rawValue &&
-            (attributeValue as! MSRPStreamIDRepresentable).streamID == talkerValue.streamID
-        }
         let talkerFailed = MSRPTalkerFailedValue(
           streamID: talkerValue.streamID,
           dataFrameParameters: talkerValue.dataFrameParameters,