[Dovecot] zlib plugin maildir broken ?/ Cached message size smaller than expected

[Robert Schetterer]

Hi Timo,
by having errors like

Cached message size smaller than expected
and
Maildir filename has wrong S value
and
Corrupted index cache file

in dove 2.1.8

i can reproduce the problem with tb 14
with 2 nat machines connected to the same server

the problem relates with create new folder then copy
some uncompressed and compressed mail to it, the i.e
open it by other client

sometime this happens at once , sometime after a few copy actions

however thunderbird ,then errors above apear, sometimes no mail is
shown, sometimes only uncompressed or only compressed

so funktion read both formats gets lost somehow
any idea, you need a better debug ?
-- 
Best Regards
MfG Robert Schetterer