rmdir: ensure proper sequence of operations

Ensure the proper sequence of opening and removing a directory. Fix a
potential race between the OpenDirectory (issued by dirlist.Select())
and the RemoveDirectory messages when removing a directory.

Due to the delay in the current dirlist.Select() function, the
RemoveDirectory message can arrive at the backend before the directory
was changed to a different one. This can cause an error on some imap
servers and problems with the watcher on the maildir backends.

Introduce dirlist.Open() that accepts a callback function so that the
operations can be performed in proper sequence. Dirlist.Select() is now
a wrapper call to dirlist.Open().

Reported-by: inwit <inwit@sindominio.net>
Signed-off-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>
Tested-by: Inwit <inwit@sindominio.net>

0 files changed, 0 insertions, 0 deletions