Added logic for not using getElementsByClassName in different failure states. Fixes jQuery bugs #4058 and #4042.

1 files changed, 15 insertions, 2 deletions

diff --git a/src/selector.js b/src/selector.js
index 5425d9482..9fb674ec3 100644
--- a/src/selector.js
+++ b/src/selector.js
@@ -741,12 +741,25 @@ if ( document.querySelectorAll ) (function(){
 	Sizzle.matches = oldSizzle.matches;
 })();
 
-if ( document.getElementsByClassName && document.documentElement.getElementsByClassName ) {
+if ( document.getElementsByClassName && document.documentElement.getElementsByClassName ) (function(){
+	var div = document.createElement("div");
+	div.innerHTML = "<div class='test e'></div><div class='test'></div>";
+
+	// Opera can't find a second classname (in 9.6)
+	if ( div.getElementsByClassName("e").length === 0 )
+		return;
+
+	// Safari caches class attributes, doesn't catch changes (in 3.2)
+	div.lastChild.className = "e";
+
+	if ( div.getElementsByClassName("e").length === 1 )
+		return;
+
 	Expr.order.splice(1, 0, "CLASS");
 	Expr.find.CLASS = function(match, context) {
 		return context.getElementsByClassName(match[1]);
 	};
-}
+})();
 
 function dirNodeCheck( dir, cur, doneName, checkSet, nodeCheck, isXML ) {
 	for ( var i = 0, l = checkSet.length; i < l; i++ ) {