Re: [patch] gnus.el::gnus-invalid-group-regexp - Support IMAP

[Simon Josefsson <jas@extundo.com>]

Reiner Steib <4.uce.03.r.s@nurfuerspam.de> writes:

> On Thu, Aug 21 2003, Simon Josefsson wrote:
>
>> Reiner Steib <4.uce.03.r.s@nurfuerspam.de> writes:
>>
>>> On Tue, Aug 19 2003, Simon Josefsson wrote:
>>>
>>>> A potential problem may be if you create, e.g., a nnml or nnfolder
>>>> group with the name containing '/'.  Does it work?  With Agent/Caching
>>>> too?  Does it do what users expect?  With all
>>>> nnmail-use-long-file-names settings?  No problems with having two
>>>> groups 'foo' and 'foo/bar'?  Many questions.
> [...]
>>> - The problem that we were discussing was only the character `/' in
>>>   IMAP groups.  I don't think it's a good idea to let the user create
>>>   _any_ invalid group, e.g. with [: `'\"] and even empty group names.
>>
>> All of those characters are valid in IMAP, 
>
> Okay, we can change the "(string-match "/" match)" part.  But at least
> empty or other group names, that will most probably fail when used in
> Gnus groups (which chars?) sooner or later[1] should remain forbidden,
> IMHO.  If the user is absolutely sure, he can always customize
> `gnus-invalid-group-regexp'.

Of the default values in gnus-invalid-group-regexp, I think only the :
and empty group name are really off-limit.  The others look even
likely to occur, and should work.

>> and since some IMAP servers export regular file systems ($HOME/), I
>> think it is even likely that people have group names containing some
>> of those characters.
>
> I know that it exists, but I remembered some problems related to this,
> e.g. with "Unerwünschte Nachrichten" (?).

There is code to IMAP-UTF-7 encode at least ISO-8859-1 characters, and
it used to work when I tried it long time ago; I used to name my spam
folder as INBOX.räksmörgås.  Doesn't it work?

Perhaps we should add a UTF-7 coding system to Emacs, btw...

> [1] Will Gcc to a group containing `"' work?  And the other issues you
>     mentioned previously (see quote at the top).

Maybe if you put a

Gcc: "nnimap+foo:bar\"baz"

although I haven't tested it, although quoted Gcc group names should
be supported.  Hm.  I recall there actually being some low-level
imap.el bug when " is used in a mailbox name though, it doesn't use a
literal instead of a string, which is necessary in the IMAP protocol,
IIRC.