Two or three days ago I was cleaning up my webserver hosts, and adding some stuff.
Occasionally, I've created a file with name containing '?'(question sign) in it. This directory had autoindex enabled, served by nginx.
I've tried to view the directory listing in my browser(just to see how it is shown) and found a bug: autoindex module wasn't URL-encoding the question sign. So it resulted in request to /somedir/filename instead of /somedir/filename%3f as it should have been.