Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!pasteur!agate!ucbvax!hplabs!hpda!hptsug2!taylor@hplabs.HP.COM
From: taylor@hplabs.HP.COM (Dave Taylor)
Newsgroups: comp.mail.elm
Subject: Re: Let's call it a wrap?
Message-ID: <478@hptsug2.HP.COM>
Date: 30 Aug 88 17:35:45 GMT
References: <3873@pbhyf.PacBell.COM>
Sender: taylor@hptsug2.HP.COM
Organization: Hewlett-Packard University Grants Program
Lines: 33

Rob Bernardo copies a message he (presumably) sent to the Elm testers
mailing list with the bug report:

> .. the only outstanding bug that has been reported is a highly 
> intermittent one.  It involves incorrect offsets into the letters 
> in a mail folder and seems to occur when new mail comes in to a 
> folder already being read by Elm.  This causes the viewing of one 
> letter to include some lines from adjacent letters.

Actually I recently had some interesting insight into this problem,
though I haven't been able to look at the code to confirm my
suspicion.

Basically, I had Elm up in a window and was dinking about in /tmp in
another when a message arrived.  For another reason entirely I did a
"ls -l" of /tmp and noticed, much to my suprise, that the /tmp/mbox.taylor
file was *the size of the new message* rather than total mailbox size.

I then went into /usr/mail (I'm on a Sys V machine) and looked at the
size of the mailbox there -- sure enough it was the correct, larger
size.  Since an open file can be removed without affecting programs that
have it open for reading, I surmise that the problem we see is somehow
caused by the program having the mailbox file open when it thinks it is
closed, then attempting to "append" the new message to the temporary
mailbox, then instead, for some mysterious reason, *replacing* it
instead.  

Most peculiar indeed.

This might, I hope, help someone track the problem down, however.

						-- Dave Taylor

purported author, The Elm Mail System  ;-)