expand_dir.js is buggy on table layouts

[palgarvio]

When creating a custom template to trac I found out that expand_dir.js show's buggy behaviour on table layouts.

When looking for parents, the script should only use the first one found, not all parents().

Here's a patch:

trac/htdocs/js/expand_dir.js

@@ -40 +40 @@
 
   // handler for click event on the expander icons
   window.toggleDir = function(expander, qargs) {
-    var tr = expander.parents("tr");
+    var tr = expander.parents("tr:first");
     var folderid = tr.get(0).id;
 
     if ( tr.filter(".expanded").length ) { // then *fold*

Yes, I know table layouts should be avoided, but that's not the issue here, the issue is making the script work better/as expected.

[cboos]

Requested again in #7634...

[cboos]

Suggested fix applied in r7543.