UPDATE SIZZLE: completed rewrite for better things!

Remove reverse in traversing for comma selectors. Sizzle's handling of commas is now more consistent.

src/traversing.js

@@ -1,7 +1,5 @@
 var runtil = /Until$/,
-	rparentsprev = /^(?:parents|prevUntil|prevAll)/,
-	// Note: This RegExp should be improved, or likely pulled from Sizzle
-	rmultiselector = /,/,
+	rparentsprev = /^(?:parents|prev(?:Until|All))/,
 	isSimple = /^.[^:#\[\.,]*$/,
 	POS = jQuery.expr.match.globalPOS,
 	// methods guaranteed to produce a unique set when starting from a unique set
@@ -217,7 +215,7 @@ jQuery.each({
 
 		ret = this.length > 1 && !guaranteedUnique[ name ] ? jQuery.unique( ret ) : ret;
 
-		if ( (this.length > 1 || rmultiselector.test( selector )) && rparentsprev.test( name ) ) {
+		if ( this.length > 1 && rparentsprev.test( name ) ) {
 			ret = ret.reverse();
 		}