Bringing back the change from 80a4178a,...

Bringing back the change from 80a4178a, adapted to handle both the function collision and the issue mentioned in #7196.

src/ajax.js

@@ -239,10 +239,6 @@ jQuery.extend({
 			var customJsonp = window[ jsonp ];
 
 			window[ jsonp ] = function( tmp ) {
-				data = tmp;
-				jQuery.handleSuccess( s, xhr, status, data );
-				jQuery.handleComplete( s, xhr, status, data );
-
 				if ( jQuery.isFunction( customJsonp ) ) {
 					customJsonp( tmp );
 
@@ -254,6 +250,10 @@ jQuery.extend({
 						delete window[ jsonp ];
 					} catch( jsonpError ) {}
 				}
+
+				data = tmp;
+				jQuery.handleSuccess( s, xhr, status, data );
+				jQuery.handleComplete( s, xhr, status, data );
 				
 				if ( head ) {
 					head.removeChild( script );