By default, use document root rather than current selection's context…

… when add()ing elements. Fixes #7853.

src/traversing.js

@@ -134,7 +134,7 @@ jQuery.fn.extend({
 
 	add: function( selector, context ) {
 		var set = typeof selector === "string" ?
-				jQuery( selector, context || this.context ) :
+				jQuery( selector, context ) :
 				jQuery.makeArray( selector ),
 			all = jQuery.merge( this.get(), set );
 

test/unit/traversing.js

@@ -440,12 +440,13 @@ test("add(String|Element|Array|undefined)", function() {
 
 test("add(String, Context)", function() {
 	expect(6);
-
-	equals( jQuery(document).add("#form").length, 2, "Make sure that using regular context document still works." );
-	equals( jQuery(document.body).add("#form").length, 2, "Using a body context." );
-	equals( jQuery(document.body).add("#html").length, 1, "Using a body context." );
-
-	equals( jQuery(document).add("#form", document).length, 2, "Use a passed in document context." );
-	equals( jQuery(document).add("#form", document.body).length, 2, "Use a passed in body context." );
-	equals( jQuery(document).add("#html", document.body).length, 1, "Use a passed in body context." );
+
+	equals( jQuery("#firstp").add("#ap").length, 2, "Add selector to selector" );
+	equals( jQuery(document.getElementById("firstp")).add("#ap").length, 2, "Add gEBId to selector" );
+	equals( jQuery(document.getElementById("firstp")).add(document.getElementById("ap")).length, 2, "Add gEBId to gEBId" );
+
+	var ctx = document.getElementById("firstp");
+	equals( jQuery("#firstp").add("#ap", ctx).length, 1, "Add selector to selector with context" );
+	equals( jQuery(document.getElementById("firstp")).add("#ap", ctx).length, 1, "Add gEBId to selector with context" );
+	equals( jQuery(document.getElementById("firstp")).add(document.getElementById("ap"), ctx).length, 2, "Add gEBId to gEBId with context" );
 });