User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040707 Firefox/0.9.2 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040707 Firefox/0.9.2 Take a look at the two spam comments there They are a valid anchor according to my eyes and W3C Validator (though the page in itself isn't valid, has some bugs in it, oh well), yet they don't show the URL hreffed by them. No JavaScript is involved. Reproducible: Didn't try Steps to Reproduce:

Nothing to do with the HTML parser. The problem is that after unescaping the URI contains bytes that are not valid UTF-8. Since the page is UTF-8, we fail to convert the string into Unicode for display. Should we just use the escaped URI in the status bar in cases when the conversion fails, perhaps? That may have security implications, but so does showing nothing... Note: the relevant code is nsWebShell::OnOverLink

dup of Bug 244754?

Yes, exact same problem. Didn't manage to find it in search, sorry. *** This bug has been marked as a duplicate of 244754 ***