checkout: don't crash on file checkout before running post-checkout hook
In the case of
git init
echo exit >.git/hooks/post-checkout
chmod +x .git/hooks/post-checkout
touch foo
git add foo
rm foo
git checkout -- foo
git-checkout resulted in a Segmentation fault, because there is no new
branch set for the post-checkout hook.
This patch makes use of the null SHA as it is set for the old branch.
While at it, I removed the xstrdup() around the sha1_to_hex(...) calls
in builtin-checkout.c/post_checkout_hook() because sha1_to_hex()
uses four buffers for the hex-dumped SHA and we only need two.
(Duplicating one buffer is only needed if we need more than four.)
Signed-off-by: Stephan Beyer <s-beyer@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin-checkout.c b/builtin-checkout.c
index b5dd9c0..149343e 100644
--- a/builtin-checkout.c
+++ b/builtin-checkout.c
@@ -47,8 +47,10 @@
memset(&proc, 0, sizeof(proc));
argv[0] = name;
- argv[1] = xstrdup(sha1_to_hex(old ? old->object.sha1 : null_sha1));
- argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
+ argv[1] = sha1_to_hex(old ? old->object.sha1 : null_sha1);
+ argv[2] = sha1_to_hex(new ? new->object.sha1 : null_sha1);
+ /* "new" can be NULL when checking out from the index before
+ a commit exists. */
argv[3] = changed ? "1" : "0";
argv[4] = NULL;
proc.argv = argv;
