Debugging a seldom seen bug (C-g with Ido)

[Vasilii Kolobkov <vasilii@orangeshoelaces.net>]

Hello Emacs fellows!

I've been living with a minor nuisance of a bug for a long time with
little success in finding the root cause and thought maybe it's time to
solicit some hints from you!

I'm using Ido for all my completion needs, and occasionally when i'm
trying to abort an active ido-find-file command with C-g, i'm getting
"[Quit]" appended to the minibuffer, rather than the operation being
aborted.  As if the keyboard-quit was processed while some buffer other
than minibuffer was current.

It happens rather rarely and i failed to reliably reproduce it following
the script from view-lossage.  But still often enough to occur during a
dedicated session, so that some sort of complete execution trace of a
process to be feasible.

I'd be very much grateful for any ideas on how to pinpoint such a
critter.