Comment 2 for bug 495029

This is due to the upgrade in YUI. The dupefinder was written and mostly QA'd against a branch which used the pre-release YUI3, which expected Y.all() to return null when no matching nodes were found. The released version of YUI3's Y.all() returns an empty NodeList when no nodes are found. Since the change for Y.Lang.isValue() on such results would now always return true, the JS assumed that there were duplicates found when there weren't and so would never show the filebug form in those cases.

The fix for this is to convert the Y.Lang.isValue() checks on the results of Y.all() to use result.size() > 0.