Mail crash isolated - DBMail imap interaction

Question

To all,
This is not a question as much as as a heads-up in case people are having the same problem.
My ISP has spent the better part of the weekend tracking down a DBMail imap bug that causes the Mail app to crash (sometimes within seconds of launching Mail, sometimes taking closer to 5 minutes after launching Mail).
Below is what was reported from one engineer to another.
Side note. The ISP (speedsite.com) is owned by an ex-NeXT person. All the development staff at the ISP (they provide consulting to corporates in addition to ISP services) use Apple portables. Cal and I both worked for NeXT back when NeXT had black hardware.
Subject: DBMail improperly re-rendering MIME BODYSTRUCTURE empty "inline" records
Matt,
Here is what I saw with a protocol comparison between octo on ports 143 (ordinary imap & Maildir) and 144 (DBMail imap).
The "inline" specifier was not being given a NIL argument when it had no arguments under DBMail as it properly was under Maildir.
Chased down the code base and noticed there were two places in the code base where a check for no arguments to "inline" was tested.
In the first test, if there were no arguments for "inline", then nothing would be printed and the second test was bypassed.
In the second test, a NIL would have been printed, but it was in a section of orphaned code that never gets executed having failed the first test.
So, I commented out the first test (see below), which un-orphaned code fragment in the second test and now "inline" is properly rendered.
Apple's Mail.app has not died since. Mail.app's intolerance to semantic sloppiness in Imap's rendering of MIME documents caused Mail.app to dump core.
[/usr/src/svn/dbmail] root@octo# diff dm_imaputil.c ../dbmail-clean/dm_imaputil.c
194c197
< /* if (disposition->param_hash) */
if (disposition->param_hash)
The version of dbmail-imapd running on octo at the moment is the debugging version you were testing with along with my single change and had not been installed properly.
Mail.app would only fail in cases where "inline" specifiers in MIME documents were not given a NIL argument in cases where there were no arguments for "inline".
Thanks
Cal
From Matt to Cal and I:
The patch was accepted by the dbmail folks (RFC violation). We should
forward the specific issue to Apple so they know where the problem was
coming from. Mail.app should not crash in the face of malformed input.
------

Answer 1

There is no 'answer' but there is some useful comments posted in the thread.