jquery core: closes #2930. Normalizing attr() to return undefined, even when getting...

diff --git a/src/core.js b/src/core.js
index d46f89d..478de97 100644 (file)
--- a/src/core.js
+++ b/src/core.js
@@ -1060,7 +1060,7 @@ jQuery.extend({
                                elem.parentNode.selectedIndex;
 
                        // If applicable, access the attribute via the DOM 0 way
-                       if ( notxml && !special && name in elem ) {
+                       if ( name in elem && notxml && !special ) {
                                if ( set ){
                                        // We can't allow the type property to be changed (since it causes problems in IE)
                                        if ( name == "type" && jQuery.nodeName( elem, "input" ) && elem.parentNode )
@@ -1083,11 +1083,13 @@ jQuery.extend({
                                // convert the value to a string (all browsers do this but IE) see #1070
                                elem.setAttribute( name, "" + value );
 
-                       if ( msie && special && notxml )
-                               return elem.getAttribute( name, 2 );
-
-                       return elem.getAttribute( name );
+                       var attr = msie && notxml && special
+                                       // Some attributes require a special call on IE
+                                       ? elem.getAttribute( name, 2 )
+                                       : elem.getAttribute( name );
 
+                       // Non-existent attributes return null, we normalize to undefined
+                       return attr === null ? undefined : attr;
                }
 
                // elem is actually elem.style ... set the style