Fixed tabindex normalization so that elements that natively support tabbing,...

Fixed tabindex normalization so that elements that natively support tabbing, but don't have a tabindex explicitly set return 0 instead of undefined.

Removed jQuery.support.tabindex since we're only normalizing non-XML right now and all browsers support tabIndex for HTML documents.

src/core.js

@@ -968,11 +968,15 @@ jQuery.extend({
 				if( jQuery.nodeName( elem, "form" ) && elem.getAttributeNode(name) )
 					return elem.getAttributeNode( name ).nodeValue;
 
-				// elem.tabindex doesn't always return the correct value
+				// elem.tabIndex doesn't always return the correct value when it hasn't been explicitly set
 				// http://fluidproject.org/blog/2008/01/09/getting-setting-and-removing-tabindex-values-with-javascript/
-				if ( name == jQuery.props.tabindex ) {
-					var attributeNode = elem.getAttributeNode(jQuery.props.tabindex);
-					return attributeNode && attributeNode.specified && attributeNode.value || undefined;
+				if ( name == "tabIndex" ) {
+					var attributeNode = elem.getAttributeNode( "tabIndex" );
+					return attributeNode && attributeNode.specified
+						? attributeNode.value
+						: elem.nodeName.match(/^(a|area|button|input|object|select|textarea)$/i)
+							? 0
+							: undefined;
 				}
 
 				return elem[ name ];

src/support.js

@@ -51,10 +51,6 @@
 		// (IE uses styleFloat instead of cssFloat)
 		cssFloat: !!a.style.cssFloat,
 
-		// Verify tabindex attribute existence
-		// (IE uses tabIndex instead of tabindex)
-		tabindex: !a.getAttributeNode('tabindex'),
-
 		// Will be defined later
 		scriptEval: false,
 		noCloneEvent: true
@@ -101,5 +97,5 @@ jQuery.props = {
 	maxlength: "maxLength",
 	cellspacing: "cellSpacing",
 	rowspan: "rowSpan",
-	tabindex: jQuery.support.tabindex ? "tabindex" : "tabIndex"
+	tabindex: "tabIndex"
 };

test/unit/core.js

@@ -562,7 +562,7 @@ test("attr('tabindex')", function() {
 	equals(jQuery('#divWithNoTabIndex').attr('tabindex'), undefined, 'no tabindex, not tabbable by default');
 
     // link without a tabindex
-	equals(jQuery('#linkWithNoTabIndex').attr('tabindex'), undefined, 'no tabindex, tabbable by default');
+	equals(jQuery('#linkWithNoTabIndex').attr('tabindex'), 0, 'no tabindex, tabbable by default');
 });
 
 test("attr('tabindex', value)", function() {
@@ -1560,7 +1560,7 @@ test("removeClass(String) - simple", function() {
 });
 
 test("toggleClass(String)", function() {
-	expect(6);
+	expect(6);
 	var e = jQuery("#firstp");
 	ok( !e.is(".test"), "Assert class not present" );
 	e.toggleClass("test");
@@ -1568,12 +1568,12 @@ test("toggleClass(String)", function() {
 	e.toggleClass("test");
 	ok( !e.is(".test"), "Assert class not present" );
 
-	e.toggleClass("test", false);
-	ok( !e.is(".test"), "Assert class not present" );
-	e.toggleClass("test", true);
-	ok( e.is(".test"), "Assert class present" );
-	e.toggleClass("test", false);
-	ok( !e.is(".test"), "Assert class not present" );
+	e.toggleClass("test", false);
+	ok( !e.is(".test"), "Assert class not present" );
+	e.toggleClass("test", true);
+	ok( e.is(".test"), "Assert class present" );
+	e.toggleClass("test", false);
+	ok( !e.is(".test"), "Assert class not present" );
 });
 
 test("removeAttr(String", function() {