bug#21057: [PATCH] nnimap.el: add support for IMAP namespaces

[Nikolaus Rath]

Package: gnus
Tags: patch

Hello,

The attached patch adds basic support for IMAP namespaces to nnimap. If
the new server variable nnimap-use-namespaces is t, Gnus will attempt to
determine the user's personal namespace (e.g. "INBOX."). When reading
the list of mail folders, this prefix will be stripped. If there are
folders outside the users personal namespace, they will be prefixed with
the breakout character (#).

This is useful for servers where all personal mailboxes appear is
subfolders of the user's INBOX. For example, before the patch one would
have:

nnimap+fm:INBOX
nnimap+fm:INBOX.Sent Items
nnimap+fm:INBOX.Drafts
nnimap+fm:INBOX.Archive
nnimap+fm:Shared.Bob.INBOX

and afterwards:

nnimap+fm:INBOX
nnimap+fm:Sent Items
nnimap+fm:Drafts
nnimap+fm:Archive
nnimap+fm:#Shared.Bob.INBOX


I have only tested this on my personal account, so feedback is
appreciated.

Thanks for considering,
-Nikolaus