Remove conditional that prevents attr from working on non-Element nodes. Fixes #7451.

src/attributes.js

@@ -289,8 +289,6 @@ jQuery.extend({
 		// Try to normalize/fix the name
 		name = notxml && jQuery.props[ name ] || name;
 
-		// Only do all the following if this is a node (faster for style)
-		if ( elem.nodeType === 1 ) {
 		// These attributes require special treatment
 		var special = rspecialurl.test( name );
 
@@ -374,7 +372,6 @@ jQuery.extend({
 		// Non-existent attributes return null, we normalize to undefined
 		return attr === null ? undefined : attr;
 	}
-	}
 });
 
 })( jQuery );

test/unit/attributes.js

@@ -4,7 +4,7 @@ var bareObj = function(value) { return value; };
 var functionReturningObj = function(value) { return (function() { return value; }); };
 
 test("attr(String)", function() {
-	expect(30);
+	expect(31);
 
 	// This one sometimes fails randomly ?!
 	equals( jQuery('#text1').attr('value'), "Test", 'Check for value attribute' );
@@ -65,6 +65,8 @@ test("attr(String)", function() {
 
 	ok( jQuery("<div/>").attr("doesntexist") === undefined, "Make sure undefined is returned when no attribute is found." );
 	ok( jQuery().attr("doesntexist") === undefined, "Make sure undefined is returned when no element is there." );
+
+	equals( jQuery(document).attr("nodeName"), "#document", "attr works correctly on document nodes (bug #7451)." );
 });
 
 if ( !isLocal ) {