I stumbled upon a bizarre WPMu comments bug today (it may also effect single WP installs, but I’m not sure). Here’s the skinny, if you include to: with two trailing spaces, you will not be able to post a comment on UMW Blogs or bavatuesdays. I’m not sure this is true for all WPMu sites, and I guess others would have to test it for certainty, but it is definitely the case on the two WPMu installs I have tested it on. As soon as you try and post the comment containing the to: with two trailing spaces it will throw a 404 error. Think I’m kidding? Try and comment here with a to: and two spaces, I dare you, hippie. Heck, I’ll even give you 100 bucks if it gets through.
Thanks go to Patrick for knowing about this bug and helping me trouble shoot it, I would have been flummoxed without him.
Update: Even more bizarre is that I tried posting this post with the to: and two trailing spaces and it wouldn’t let me publish the post either, it just threw a 404 error. Wow, what a strange, strange bug.
Weird–it seems to work fine on a test blog on our wpmu install, both in posts and in comments. I can definitely replicate the error here, at bavatuesdays, but not on ours.
Example
http://macaulay.cuny.edu/eportfolios/kirk/2008/09/18/testing-jims-bug/
Thanks for testing this Joe. I was afraid of that. This means one of two things, it’s a plugin (most likely). Or it is related to subdomains, chances are though it’s a plugin which means I have some debugging to do 🙁
The symptoms sound a little like a mod_security error in Apache… some rule that is being triggered in the payload of forms. If you control your server, test with mod_security off (if it is running) or look in the appropriate logs?