Allow similarly named classes (regression from 9499) and switch class…

… retrieval to property when passing class to value functions. Fixes #9617.

@@ -37,12 +37,12 @@ jQuery.fn.extend({
 	},
 
 	addClass: function( value ) {
-		var classNames, i, l, elem, setClass, c, cl;
+		var classNames, i, l, elem,
+			setClass, c, cl;
 
 		if ( jQuery.isFunction( value ) ) {
 			return this.each(function( j ) {
-				var self = jQuery( this );
-				self.addClass( value.call(this, j, self.attr("class") || "") );
+				jQuery( this ).addClass( value.call(this, j, this.className) );
 			});
 		}
 
@@ -57,11 +57,11 @@ jQuery.fn.extend({
 						elem.className = value;
 
 					} else {
-						setClass = elem.className;
+						setClass = " " + elem.className + " ";
 
 						for ( c = 0, cl = classNames.length; c < cl; c++ ) {
-							if ( !~setClass.indexOf(classNames[ c ]) ) {
-								setClass += " " + classNames[ c ];
+							if ( !~setClass.indexOf( " " + classNames[ c ] + " " ) ) {
+								setClass += classNames[ c ] + " ";
 							}
 						}
 						elem.className = jQuery.trim( setClass );
@@ -78,8 +78,7 @@ jQuery.fn.extend({
 
 		if ( jQuery.isFunction( value ) ) {
 			return this.each(function( j ) {
-				var self = jQuery( this );
-				self.removeClass( value.call(this, j, self.attr("class")) );
+				jQuery( this ).removeClass( value.call(this, j, this.className) );
 			});
 		}
 
@@ -112,9 +111,8 @@ jQuery.fn.extend({
 			isBool = typeof stateVal === "boolean";
 
 		if ( jQuery.isFunction( value ) ) {
-			return this.each(function(i) {
-				var self = jQuery(this);
-				self.toggleClass( value.call(this, i, self.attr("class"), stateVal), stateVal );
+			return this.each(function( i ) {
+				jQuery( this ).toggleClass( value.call(this, i, this.className, stateVal), stateVal );
 			});
 		}
 

@@ -762,7 +762,8 @@ test("val(select) after form.reset() (Bug #2551)", function() {
 }); 
 
 var testAddClass = function(valueObj) {
-	expect(7);
+	expect(9);
+
 	var div = jQuery("div");
 	div.addClass( valueObj("test") );
 	var pass = true;
@@ -791,10 +792,16 @@ var testAddClass = function(valueObj) {
 	div.addClass( valueObj("bar baz") );
 	equals( div.attr("class"), "foo bar baz", "Make sure there isn't too much trimming." );
 	
-	div.removeAttr("class");
+	div.removeClass();
 	div.addClass( valueObj("foo") ).addClass( valueObj("foo") )
 	equal( div.attr("class"), "foo", "Do not add the same class twice in separate calls." );
-	div.removeAttr("class");
+
+	div.addClass( valueObj("fo") );
+	equal( div.attr("class"), "foo fo", "Adding a similar class does not get interrupted." );
+	div.removeClass().addClass("wrap2");
+	ok( div.addClass("wrap").hasClass("wrap"), "Can add similarly named classes");
+
+	div.removeClass();
 	div.addClass( valueObj("bar bar") );
 	equal( div.attr("class"), "bar", "Do not add the same class twice in the same call." );
 };
@@ -959,7 +966,7 @@ test("toggleClass(Function[, boolean])", function() {
 test("toggleClass(Fucntion[, boolean]) with incoming value", function() {
 	expect(14);
 
-	var e = jQuery("#firstp"), old = e.attr("class");
+	var e = jQuery("#firstp"), old = e.attr("class") || "";
 	ok( !e.is(".test"), "Assert class not present" );
 
 	e.toggleClass(function(i, val) {