bug#23619: Some epg tests fail

[Daiki Ueno]

npostavs@users.sourceforge.net writes:

> tags 23619 patch
> quit
>
> Glenn Morris <rgm@gnu.org> writes:
>
>> Two epg tests fail for me on RHEL 7.2 with current master (and have done
>> since they stopped being skipped).
>>
>> gpg --version
>> gpg (GnuPG) 2.0.22
>> libgcrypt 1.5.3
>
>> 2 unexpected results:
>>    FAILED  epg-decrypt-1
>>    FAILED  epg-roundtrip-1
>
> I have
>
>     gpg --version
>     gpg (GnuPG) 2.1.18
>     libgcrypt 1.7.6
>
> These tests popup a dialog box to enter a passphrase before failing.
> The following patch which sets pinentry mode to 'loopback' fixes it for
> me (I have not tested with other gpg versions though):

Thank you.  That sounds like a good idea, but the version actually
matters: gpg 1.x and 2.0.x refuse the --pinentry-mode option and exit
abnormally...

Maybe you could add a version check around the call (or in epg--start)?
epg-config.el provides a few functions to do that.

Regards,
-- 
Daiki Ueno