Woodchuck <djv@bedford.net> writes:
> I suspect mtree, the command that seemed to have most recently
> executed.  A cursory inspection of the source in
> /usr/src/usr.sbin/mtree/mtree.c shows this bit of code near the
> end:
>
> 	status = verify();
> 	if (Uflag & (status == MISMATCHEXIT))
> 		status = 0;
> 	exit(status);
> }
>
> I feel like putting in a spoiler gap here, so that readers could
> try to "spot that bug", but I won't ;-)
>
> Long experience suggests to me that the if statement should read
> 	if (Uflag && (status == MISMATCHEXIT))
> I say that without analyzing the code.

Indeed it should (and I've fixed it in -current), but in fact the code
works just fine. status == MISMATCHEXIT yields a value of 1 (at least
in a standards compliant compiler like gcc), which, when anded bitwise
with 1 (Uflag is 1 or 0), produces the correct result.

Naturally, this is an abuse, which is why I've commited a fix to -current.

However, this is quite clearly not causing you a problem -- my
alteration is not even going to change the execution behavior.

> I have a sense of deja-vu about mtree and this particular bug, I
> seem to recall hacking at it many years ago in a different OS.

Perhaps, but that code is NetBSD specific and only a few years old.

Perry