[dovecot/core] 42f520: dsync: Fix potential assert on mailbox deinit.

[GitHub]

  Branch: refs/heads/master-2.2
  Home:   https://github.com/dovecot/core
  Commit: 42f5200012b86c3e4a1f358564bf879d9c93faa9
      https://github.com/dovecot/core/commit/42f5200012b86c3e4a1f358564bf879d9c93faa9
  Author: Timo Sirainen <timo.sirainen at dovecot.fi>
  Date:   2016-10-28 (Fri, 28 Oct 2016)

  Changed paths:
    M src/doveadm/dsync/dsync-brain-mailbox.c

  Log Message:
  -----------
  dsync: Fix potential assert on mailbox deinit.

Should have happened only in somewhat rare error conditions that require
resyncing.

Fixes:
Panic: file dsync-brain-mailbox.c: line 358 (dsync_brain_sync_mailbox_deinit): assertion failed: (brain->failed || brain->sync_type == DSYNC_BRAIN_SYNC_TYPE_CHANGED)