Propagete context of returned deferred object in Deferred.then(). Fixes #13160

Author: nanto

src/deferred.js

@@ -35,7 +35,9 @@ jQuery.extend({
 										newDefer[ action + "With" ]( this === promise ? newDefer.promise() : this, [ returned ] );
 									}
 								} :
-								newDefer[ action ]
+								function() {
+									newDefer[ action + "With" ]( this === promise ? newDefer.promise() : this, arguments );
+								}
 							);
 						});
 						fns = null;
@@ -72,7 +74,7 @@ jQuery.extend({
 
 			// deferred[ resolve | reject | notify ]
 			deferred[ tuple[0] ] = function() {
-				deferred[ tuple[0] + "With" ]( promise, arguments );
+				deferred[ tuple[0] + "With" ]( this === deferred ? promise : this, arguments );
 				return this;
 			};
 			deferred[ tuple[0] + "With" ] = list.fireWith;

test/unit/deferred.js

@@ -273,7 +273,7 @@ test( "jQuery.Deferred.then - deferred (progress)", function() {
 
 test( "jQuery.Deferred.then - context", function() {
 
-	expect( 4 );
+	expect( 7 );
 
 	var context = {};
 
@@ -284,6 +284,12 @@ test( "jQuery.Deferred.then - context", function() {
 		strictEqual( value, 6, "proper value received" );
 	});
 
+	jQuery.Deferred().resolve().then(function() {
+		return jQuery.Deferred().resolveWith(context);
+	}).done(function() {
+		strictEqual( this, context, "custom context of returned deferred correctly propagated" );
+	});
+
 	var defer = jQuery.Deferred(),
 		piped = defer.then(function( value ) {
 			return value * 3;
@@ -295,6 +301,16 @@ test( "jQuery.Deferred.then - context", function() {
 		strictEqual( this, piped, "default context gets updated to latest promise in the chain" );
 		strictEqual( value, 6, "proper value received" );
 	});
+
+	var defer2 = jQuery.Deferred(),
+		piped2 = defer2.then();
+
+	defer2.resolve( 2 );
+
+	piped2.done(function( value ) {
+		strictEqual( this, piped2, "default context gets updated to latest promise in the chain (without passing function)" );
+		strictEqual( value, 2, "proper value received (without passing function)" );
+	});
 });
 
 test( "jQuery.when", function() {