Possible memory corruption problem

[Piet van Oostrum]

I have had a few occasions when my mailboxes got corrupted.
I read my normal email with VM, and mail from mailing lists with gnus. I
have CVS emacs compiled about a month ago, running on Mac OS X 10.4.4.

A few cases now, the last of which was last weekend, the mailboxes that I
had open got completely mixed up. I lost my INBOX (primary VM mailbox)
completely last night, and some of its messages where found in the middle
of another mailbox that I had open. The mixup also occurred around last
Christmas with VM and gnus mailboxes mixed up. Sometimes the corrupted
mailboxes appeared to contain garbage text from other files.

My mailboxes are usually the largest files that I have open in Emacs, a few
MB each.

I have tried to find the common circumstances when this happens and it
aeems to me that it happens when the machine is low on virtual memory
(including swap space). So I suspect that some part of Emacs' buffer and
memory management fails to check the result of malloc calls or something
similar. I have written a test program and it appears that Mac OS X's
malloc and realloc correctly return NULL when the process runs out of
memory. 

I am sorry I can't give any more details at the moment. However I can add
that Emacs did not crash in the cases mentioned.
-- 
Piet van Oostrum <address@hidden>
URL: http://www.cs.uu.nl/~piet [PGP 8DAE142BE17999C4]
Private email: address@hidden