- "+": function(checkSet, part){
- for ( var i = 0, l = checkSet.length; i < l; i++ ) {
- var elem = checkSet[i];
- if ( elem ) {
- var cur = elem.previousSibling;
- while ( cur && cur.nodeType !== 1 ) {
- cur = cur.previousSibling;
- }
- checkSet[i] = typeof part === "string" ?
- cur || false :
- cur === part;
+ "+": function(checkSet, part, isXML){
+ var isPartStr = typeof part === "string",
+ isTag = isPartStr && !/\W/.test(part),
+ isPartStrNotTag = isPartStr && !isTag;
+
+ if ( isTag && !isXML ) {
+ part = part.toUpperCase();
+ }
+
+ for ( var i = 0, l = checkSet.length, elem; i < l; i++ ) {
+ if ( (elem = checkSet[i]) ) {
+ while ( (elem = elem.previousSibling) && elem.nodeType !== 1 ) {}
+
+ checkSet[i] = isPartStrNotTag || elem && elem.nodeName === part ?
+ elem || false :
+ elem === part;