Ensure that pre-handshake backlog is completed successfully; also simplify how...

Ensure that pre-handshake backlog is completed successfully; also simplify how sent messages get the exception recorded; can massively simplify if we know we've already burned the connection

StackExchange.Redis/StackExchange/Redis/Message.cs

@@ -599,6 +599,11 @@ internal void Fail(ConnectionFailureType failure, Exception innerException)
             resultProcessor?.ConnectionFail(this, failure, innerException);
         }
 
+        internal void SetException(Exception exception)
+        {
+            resultBox?.SetException(exception);
+        }
+
         internal void SetEnqueued()
         {
             performance?.SetEnqueued();

StackExchange.Redis/StackExchange/Redis/PhysicalBridge.cs

@@ -335,7 +335,11 @@ private void AbandonPendingBacklog(Exception ex)
             do
             {
                 next = DequeueNextPendingBacklog();
-                next?.Cancel(ex);
+                if(next != null)
+                {
+                    next.Cancel(ex);
+                    CompleteSyncOrAsync(next);
+                }
             } while (next != null);
         }
         internal void OnFullyEstablished(PhysicalConnection connection)

StackExchange.Redis/StackExchange/Redis/PhysicalConnection.cs

@@ -247,7 +247,7 @@ void add(string lk, string sk, string v)
                 {
                     var next = outstanding.Dequeue();
                     Bridge.Trace("Failing: " + next);
-                    next.Fail(failureType, innerException);
+                    next.SetException(innerException);
                     Bridge.CompleteSyncOrAsync(next);
                 }
             }

TestConsole/Program.cs

@@ -23,7 +23,7 @@ private static int Main()
                     EndPoints = { "127.0.0.1:6381" },
                     Password = "abc",
                 };
-                using (var conn = ConnectionMultiplexer.Connect(config, log: Console.Out))
+                using (var conn = ConnectionMultiplexer.Connect(config, log: null))
                 {
                     //Execute(conn);