Hi!
While debugging bug #33307 (http://bugs.winehq.org/show_bug.cgi?id=33307) I found a suspicious piece of code, looking like off-by-one error.
Unfortunately, I'm not familiar with this part of wine and I don't know how to write corresponding test case.
If you familiar with this module, please, take a look at this wanna-be-a-bug and the proposed patch.
-- Kirill