tenderlove/mechanize — pull request #191 by TobiX (2012-02-02 19:53:25+00:00)
Title: Don't crash on bad Content-Disposition header.

It might happen that the Content-Disposition header is present, but
parsing it might yield no filename. This fix takes care of that case.

This happened to me with an ASP.net web application spitting out something like

inline; filename*=UTF-8''X%20Y.jpg

in this header. I don't think it's useful to "fix" the Content-Disposition parser for this stupid corner case.