sizzle.js

@@ -135,18 +135,29 @@ var i,
 				String.fromCharCode( high >> 10 | 0xD800, high & 0x3FF | 0xDC00 );
 	};
 
-// Use a stripped-down slice if we can't use a native one
+// Optimize for push.apply( _, slice.call(<NodeList>, 0) )
 try {
-	slice.call( preferredDoc.documentElement.childNodes, 0 )[0].nodeType;
+	push.apply(
+		(arr = slice.call( preferredDoc.childNodes )),
+		preferredDoc.childNodes
+	);
+
+	// Slice is trivial if apply accepts NodeLists
+	slice = identity;
 } catch ( e ) {
-	slice = function( i ) {
-		var elem,
-			results = [];
-		while ( (elem = this[i++]) ) {
-			results.push( elem );
-		}
-		return results;
-	};
+	// Make sure slice accepts NodeLists
+	if ( !arr.length ) {
+		slice = function( i ) {
+			var results = [];
+			while ( (results[i] = this[i++]) ) {}
+			results.pop();
+			return results;
+		};
+	}
+}
+
+function identity() {
+	return this;
 }
 
 /**
@@ -371,25 +382,24 @@ setDocument = Sizzle.setDocument = function( node ) {
 		return div.getElementsByClassName("e").length === 2;
 	});
 
-	// Check if getElementById returns elements by name
 	// Check if getElementsByName privileges form controls or returns elements by ID
+	// If so, assume (for broader support) that getElementById returns elements by name
 	support.getByName = assert(function( div ) {
 		// Inject content
 		div.id = expando + 0;
 		// Support: Windows 8 Native Apps
 		// Assigning innerHTML with "name" attributes throws uncatchable exceptions
 		// http://msdn.microsoft.com/en-us/library/ie/hh465388.aspx
 		div.appendChild( document.createElement("a") ).setAttribute( "name", expando );
-		div.appendChild( document.createElement("div") ).setAttribute( "name", expando );
-		docElem.insertBefore( div, docElem.firstChild );
+		div.appendChild( document.createElement("i") ).setAttribute( "name", expando );
+		docElem.appendChild( div );
 
 		// Test
 		var pass = doc.getElementsByName &&
 			// buggy browsers will return fewer than the correct 2
 			doc.getElementsByName( expando ).length === 2 +
 			// buggy browsers will return more than the correct 0
 			doc.getElementsByName( expando + 0 ).length;
-		support.getIdNotName = !doc.getElementById( expando );
 
 		// Cleanup
 		docElem.removeChild( div );
@@ -424,7 +434,7 @@ setDocument = Sizzle.setDocument = function( node ) {
 		};
 
 	// ID find and filter
-	if ( support.getIdNotName ) {
+	if ( support.getByName ) {
 		Expr.find["ID"] = function( id, context ) {
 			if ( typeof context.getElementById !== strundefined && !documentIsXML ) {
 				var m = context.getElementById( id );
@@ -1877,9 +1887,8 @@ function select( selector, context, results, seed ) {
 Expr.pseudos["nth"] = Expr.pseudos["eq"];
 
 // Easy API for creating new setFilters
-function setFilters() {}
-Expr.filters = setFilters.prototype = Expr.pseudos;
-Expr.setFilters = new setFilters();
+identity.prototype = Expr.filters = Expr.pseudos;
+Expr.setFilters = new identity();
 
 // Initialize with the default document
 setDocument();