Fix for #8421. Makes sure resolveWith can be called with only one parameter.

src/core.js

@@ -837,6 +837,8 @@ jQuery.extend({
 				// resolve with given context and args
 				resolveWith: function( context, args ) {
 					if ( !cancelled && !fired && !firing ) {
+						// make sure args are available (#8421)
+						args = args || [];
 						firing = 1;
 						try {
 							while( callbacks[ 0 ] ) {

test/unit/core.js

@@ -916,7 +916,7 @@ test("jQuery.parseJSON", function(){
 
 test("jQuery._Deferred()", function() {
 
-	expect( 10 );
+	expect( 11 );
 
 	var deferred,
 		object,
@@ -1005,6 +1005,12 @@ test("jQuery._Deferred()", function() {
 	deferred.resolveWith( jQuery , [ document ] ).done( function( doc ) {
 		ok( this === jQuery && arguments.length === 1 && doc === document , "Test fire context & args" );
 	});
+
+	// #8421
+	deferred = jQuery._Deferred();
+	deferred.resolveWith().done(function() {
+		ok( true, "Test resolveWith can be called with no argument" );
+	});
 });
 
 test("jQuery.Deferred()", function() {