MHonArc Users,
I recently received a problem report about mhonarc leaving the
.mhonarc.lck around; ie. a stale lock on the archive. Fortunately,
the user was able to isolate the message the causes problem.
Apparently, some messages can cause perl itself to crash. Since perl
crashes, mhonarc has no chance to remove .mhonarc.lck (if using
directory locking LOCKMETHOD). I confirmed the crash with
Perl 5.005_03 under Solaris 2.8 and RH Linux 6.2 and Perl 5.6.0 under
Solaris 2.8. However, the message processed okay under
Win32 ActiveState Perl 5.6.0 and Win32 Cygwin Perl 5.6.1.
I have not had time to see what exactly about the message causes the
crash, but the message is a big nested multipart 240K, with HTML parts.
Also the HTML parts have stylesheets (which mhonarc attempts to
strip), but there are no binary attachments. My guess is a problem
with the regular expression engine since bad resource files have been
known to cause perl to crash (where a resource used in a regex is
not properly closed in a resource file).
Some users in the past have noted stale .mhonarc.lck directories in the
past. My guess is that these are probably due to perl crashing. If
under Unix/Linux, I recommend trying to use the flock method of locking
as documented in the LOCKMETHOD resource. If you can use it (read the
docs carefully), it will prevent a perl crash from locking your
archives.
--ewh
