@Robert: On re-reading your question I don't think this is really a bad link, contrary to the wording of the bug title (since my symptoms do match those described by the OP), it's just that the page that I talked about has a problem getting the filename of the file it's trying to show the history for, which has long since been deleted. This also has nothing to do with validating user input (which is the subject of the bug he referred to).
@Robert: On re-reading your question I don't think this is really a bad link, contrary to the wording of the bug title (since my symptoms do match those described by the OP), it's just that the page that I talked about has a problem getting the filename of the file it's trying to show the history for, which has long since been deleted. This also has nothing to do with validating user input (which is the subject of the bug he referred to).