Ticket #8753 Always set event type explicitly

src/event.js

@@ -574,6 +574,9 @@ jQuery.Event = function( src ) {
 			}
 		}
 
+		// Always ensure a type has been explicitly set
+		this.type = src.type;
+
 		// Events bubbling up the document may have been marked as prevented
 		// by a handler lower down the tree; reflect the correct value.
 		this.isDefaultPrevented = (src.defaultPrevented || src.returnValue === false ||