Don't let removeClass create attributes

src/attributes.js

@@ -51,11 +51,12 @@ jQuery.fn.extend({
 
 			for ( ; i < len; i++ ) {
 				elem = this[ i ];
-
-				if ( elem.nodeType === 1 ) {
-					cur = elem.className ?
+				cur = elem.nodeType === 1 && ( elem.className ?
 					( " " + elem.className + " " ).replace( rclass, " " ) :
-						" ";
+					" "
+				);
+
+				if ( cur ) {
 					j = 0;
 					while ( (clazz = classes[j++]) ) {
 						if ( cur.indexOf( " " + clazz + " " ) < 0 ) {
@@ -87,11 +88,13 @@ jQuery.fn.extend({
 
 			for ( ; i < len; i++ ) {
 				elem = this[ i ];
-				if ( elem.nodeType === 1 ) {
 				// This expression is here for better compressibility (see addClass)
-					cur = elem.className ?
+				cur = elem.nodeType === 1 && ( elem.className ?
 					( " " + elem.className + " " ).replace( rclass, " " ) :
-						" ";
+					""
+				);
+
+				if ( cur ) {
 					j = 0;
 					while ( (clazz = classes[j++]) ) {
 						// Remove *all* instances

test/unit/attributes.js

@@ -1052,38 +1052,36 @@ test( "addClass(Function) with incoming value", function() {
 });
 
 var testRemoveClass = function(valueObj) {
-	expect( 7 );
-
-	var $divs = jQuery("div");
+	expect( 8 );
 
-	$divs.addClass("test").removeClass( valueObj("test") );
+	var $set = jQuery("div"),
+		div = document.createElement("div");
 
-	ok( !$divs.is(".test"), "Remove Class" );
+	$set.addClass("test").removeClass( valueObj("test") );
 
-	QUnit.reset();
-	$divs = jQuery("div");
+	ok( !$set.is(".test"), "Remove Class" );
 
-	$divs.addClass("test").addClass("foo").addClass("bar");
-	$divs.removeClass( valueObj("test") ).removeClass( valueObj("bar") ).removeClass( valueObj("foo") );
+	$set.addClass("test").addClass("foo").addClass("bar");
+	$set.removeClass( valueObj("test") ).removeClass( valueObj("bar") ).removeClass( valueObj("foo") );
 
-	ok( !$divs.is(".test,.bar,.foo"), "Remove multiple classes" );
-
-	QUnit.reset();
-	$divs = jQuery("div");
+	ok( !$set.is(".test,.bar,.foo"), "Remove multiple classes" );
 
 	// Make sure that a null value doesn't cause problems
-	$divs.eq( 0 ).addClass("test").removeClass( valueObj( null ) );
-	ok( $divs.eq( 0 ).is(".test"), "Null value passed to removeClass" );
+	$set.eq( 0 ).addClass("expected").removeClass( valueObj( null ) );
+	ok( $set.eq( 0 ).is(".expected"), "Null value passed to removeClass" );
 
-	$divs.eq( 0 ).addClass("test").removeClass( valueObj("") );
-	ok( $divs.eq( 0 ).is(".test"), "Empty string passed to removeClass" );
+	$set.eq( 0 ).addClass("expected").removeClass( valueObj("") );
+	ok( $set.eq( 0 ).is(".expected"), "Empty string passed to removeClass" );
 
 	// using contents will get regular, text, and comment nodes
-	var j = jQuery("#nonnodes").contents();
-	j.removeClass( valueObj("asdf") );
-	ok( !j.hasClass("asdf"), "Check node,textnode,comment for removeClass" );
+	$set = jQuery("#nonnodes").contents();
+	$set.removeClass( valueObj("asdf") );
+	ok( !$set.hasClass("asdf"), "Check node,textnode,comment for removeClass" );
+
+
+	jQuery( div ).removeClass( valueObj("foo") );
+	strictEqual( jQuery( div ).attr("class"), undefined, "removeClass doesn't create a class attribute" );
 
-	var div = document.createElement("div");
 	div.className = " test foo ";
 
 	jQuery( div ).removeClass( valueObj("foo") );