StackExchange.Redis to consider separately Response Array as either NULL or an Empty Array.

StackExchange.Redis/StackExchange/Redis/PhysicalConnection.cs

@@ -877,9 +877,16 @@ private RawResult ReadArray(byte[] buffer, ref int offset, ref int count)
                 long i64;
                 if (!itemCount.TryGetInt64(out i64)) throw ExceptionFactory.ConnectionFailure(multiplexer.IncludeDetailInExceptions, ConnectionFailureType.ProtocolFailure, "Invalid array length", bridge.ServerEndPoint);
                 int itemCountActual = checked((int)i64);
-
-                if (itemCountActual <= 0) return RawResult.EmptyArray;
-
+                if (itemCountActual < 0)
+                {
+                    //for null response by command like EXEC, RESP array: *-1\r\n
+                    return new RawResult(ResultType.SimpleString, null, 0, 0); 
+                }
+                else if (itemCountActual == 0)
+                {
+                    //for zero array response by command like SCAN, Resp array: *0\r\n 
+                    return RawResult.EmptyArray; 
+                }
                 var arr = new RawResult[itemCountActual];
                 for (int i = 0; i < itemCountActual; i++)
                 {

StackExchange.Redis/StackExchange/Redis/RedisTransaction.cs

@@ -416,6 +416,19 @@ protected override bool SetResultCore(PhysicalConnection connection, Message mes
                                 SetResult(message, false);
                                 return true;
                             }
+                            //EXEC returned with a NULL
+                            if (!tran.IsAborted && result.IsNull)
+                            {
+                                connection.Multiplexer.Trace("Server aborted due to failed EXEC");
+                                //cancel the commands in the transaction and mark them as complete with the completion manager
+                                foreach (var op in wrapped)
+                                {
+                                    op.Wrapped.Cancel();
+                                    bridge.CompleteSyncOrAsync(op.Wrapped);
+                                }
+                                SetResult(message, false);
+                                return true;
+                            }
                             break;
                         case ResultType.MultiBulk:
                             if (!tran.IsAborted)