Re: bsd group semantics

From: Junio C Hamano <gitster@pobox.com>
Date: Mar 31, 2009, 15:55 UTC
Message-ID: <7vvdpp6623.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <20090331112637.GA1910@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 7 quoted lines

> The recently added test t1301.17 is failing for me on FreeBSD; the
> created directories don't have the GID bit set.
>
> I traced this back to the fact that FORCE_DIR_SET_GID is a no-op on
> FreeBSD due to the DIR_HAS_BSD_GROUP_SEMANTICS flag being set. I am not
> sure I understand the original reasoning for this flag at all; GID seems
> to work just fine on my FreeBSD 6.1 test system.

IIRC, DIR_HAS_BSD_GROUP_SEMANTICS means you do not have to ask explicitly with g+s to the filesystem to use the "subdirectory is owned by the same group as its parent" semantics. On SysV you have to ask; on BSD you do not have to (and do not need FORCE_DIR_SET_GID).

> The original thread is here:
>
>   http://article.gmane.org/gmane.comp.version-control.git/75999

That one was not about "you do not have to ask", but "you are not allowed to ask because the request will fail". Perhaps between FBSD4 and FBSD6 things changed, and you can now make g+s request (which I presume is still a no-op other than setting the bit on)?

Ideally the test should be checking if the subdirectory is owned by the same group as the toplevel, but that is rather hard to correctly arrange, as it depends on the set of groups the user who runs the test belongs to, how the git work tree is set up (if it is owned by his primary group or a secondary), etc.

For now, I'd suggest teaching the test not to care about g+s bit.