[imp] Blank page instead of INBOX listing

[Otto Stolz]

Dear all,

on 2007-03-27, I have written:
> I am testing Horde 3.1.3, Imp 4.1.3 + Turba 2.1.3
> under PHP 5.2.0 and Linux (Suse 10.2).
> 
> I have configured two IMAP servers.
> 
> Two users of one of those servers report that they see a blank
> page after log-in. [...] Other users of that same IMAP server [...]
> can view their INBOXes without any problem, and no similar problem
> is known from the other IMAP server.
...
> Apache`s  SSL request log has:
> ...
>> [22/Mar/2007:20:16:18 +0100] 84.159.78.105 TLSv1 DHE-RSA-AES256-SHA
>>    "GET /horde/imp/mailbox.php?mailbox=INBOX HTTP/1.1" -
>>    "https://webmailtest.rz.uni-konstanz.de/horde/imp/"
>>    "Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.8.1.3) Gecko/20070309 Firefox/2.0.0.3"
> where the "-" (instead of a number) means that no info was
> sent beyond the HTTP headers.
> 
> The PHP error log has nothing.

Thanks go to all contributors of suggestions for solving this
problem -- however all of those suggestions did not address its
real source.

Now, a colleague of mine has found the source of the problem,
via a log of the complete IMAP dialogue.

The problem is that the remote IMAP server maps all files (not
only the mailbox) of the respective user's home directory to the
IMAP address space. Those particular users have deeply nested
directory structures under their respective home directories,
including several symbolic links (IIRC, some of those symlinks
formed a loop). Hence the remote IMAP server terminated the IMAP
connection without delivering a result.

IMPs problem is that it does not issue a decent error message,
when the IMAP connection is terminated prematurely. Is there any
chance that this omission could be mended? Should I file an official
bug report?

The current IMP uses the PHP standard function imap_fetch_overview,
which apparently issues a »LIST "" *« command to the IMAP server.
In contrast, the old (pre-H3) Webmail issues a »LIST "" %« command,
which the remote IMAP server indeed can answer.

Best wishes,
   Otto Stolz