bug#15553: 24.3.50; epg.el and GnuPG 2.x cause unavoidable pinentry prompts for symmetrically encrypted files

[Daiki Ueno]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>>>> - on a headless server this can lock up Emacs
>>> That's not good.  We should try to make sure that detect the
>>> problematic situation, or make it easy for the user to get out of it
>>> (with something like a C-g).
>> I doubt such a hard lockup is possible, as epg.el uses async process.
>
> But it calls accept-process-output, so it can still get stuck.

Yes, but it's not a hard lockup.  I can get out from the loop with C-g.

And actually Emacs 24 has the code to allow pinentry to fallback into
the curses mode in that case (though the interaction is not very well).