[PATCH] clone: Supply the right commit hash to post-checkout when -b is used

[PATCH] clone: Supply the right commit hash to post-checkout when -b is used

[Björn Steinbrink]

When we use -b <branch>, we may checkout something else than what the
remote's HEAD references, but we still used remote_head to supply the
new ref value to the post-checkout hook, which is wrong.

So instead of using remote_head to find the value to be passed to the
post-checkout hook, we have to use our_head_points_at, which is always
correctly setup, even if -b is not used.

This also fixes a segfault when "clone -b <branch>" is used with a
remote repo that doesn't have a valid HEAD, as in such a case
remote_head is NULL, but we still tried to access it.

Reported-by: Devin Cofer <ranguvar@archlinux.us>
Signed-off-by: Björn Steinbrink <B.Steinbrink@gmx.de>
---
 builtin-clone.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/builtin-clone.c b/builtin-clone.c
index 4992c25..5762a6f 100644
--- a/builtin-clone.c
+++ b/builtin-clone.c
@@ -641,7 +641,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 			die("unable to write new index file");
 
 		err |= run_hook(NULL, "post-checkout", sha1_to_hex(null_sha1),
-				sha1_to_hex(remote_head->old_sha1), "1", NULL);
+				sha1_to_hex(our_head_points_at->old_sha1), "1",
+				NULL);
 
 		if (!err && option_recursive)
 			err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
-- 
1.6.5.7.g9ecb2

Re: [PATCH] clone: Supply the right commit hash to post-checkout when -b is used

[Jeff King]

On Wed, Oct 14, 2009 at 12:11:09AM +0200, Björn Steinbrink wrote:

> When we use -b <branch>, we may checkout something else than what the
> remote's HEAD references, but we still used remote_head to supply the
> new ref value to the post-checkout hook, which is wrong.
> 
> So instead of using remote_head to find the value to be passed to the
> post-checkout hook, we have to use our_head_points_at, which is always
> correctly setup, even if -b is not used.
> 
> This also fixes a segfault when "clone -b <branch>" is used with a
> remote repo that doesn't have a valid HEAD, as in such a case
> remote_head is NULL, but we still tried to access it.
> 
> Reported-by: Devin Cofer <ranguvar@archlinux.us>
> Signed-off-by: Björn Steinbrink <B.Steinbrink@gmx.de>

Acked-by: Jeff King <peff@peff.net>

Thanks.

When splitting remote_head versus our_head, I tried to find every use of
the remote head and pick the appropriate variable, but I think I just
missed this one. I gave the code another once-over and didn't see any
other spots that needed fixing.

-Peff

Re: [PATCH] clone: Supply the right commit hash to post-checkout when -b is used

[Junio C Hamano]

Jeff King <peff@peff.net> writes:

>> Reported-by: Devin Cofer <ranguvar@archlinux.us>
>> Signed-off-by: Björn Steinbrink <B.Steinbrink@gmx.de>
>
> Acked-by: Jeff King <peff@peff.net>
>
> Thanks.

Thanks; will queue on 'maint' for 1.6.5.1.