>>>>> In <b4mmze82cse.fsf@jpl.org> Katsumi Yamaoka wrote:

>>>>>> In <def1aabc-69b9-4b1d-bb84-e65c63540eac@well-done.deisui.org>
>>>>>>	Daiki Ueno wrote:

>> Try v5-10, and if your problem is not fixed, please remove me from Cc:.

> It happens with v5-10 as well.  Okay, I'll fix it by myself.

The cause is that the multibyteness of `pgg-output-buffer' is
turned off after inserting a temp file which contains GnuPG's
output, as the case may be.  It occurs while evaluating
`pgg-gpg-process-sentinel' (trunk) or `pgg-gpg-process-region'
(v5-10).  As long as I investigated, it takes place when
`coding-system-for-read' is bound to `raw-text' or `binary' and
an empty file is inserted into an empty multibyte buffer.  Here
is a test case: