rebase: pass correct arguments to post-checkout hook

If a rebase started with "rebase [--apply|--merge] <upstream> <branch>"
detects that <upstream> is an ancestor of <branch> then it fast-forwards
and checks out <branch>. Unfortunately in that case it passed the null
oid as the first argument to the post-checkout hook rather than the oid
of HEAD.

A side effect of this change is that the call to update_ref() which
updates HEAD now always receives the old value of HEAD. This provides
protection against another process updating HEAD during the checkout.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Phillip Wood 2022-01-26 13:05:38 +00:00 committed by Junio C Hamano
parent bd55eee04b
commit 69f4c23009
2 changed files with 22 additions and 9 deletions

18
reset.c
View File

@ -18,7 +18,7 @@ int reset_head(struct repository *r, struct object_id *oid, const char *action,
unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
unsigned update_orig_head = flags & RESET_ORIG_HEAD;
struct object_id head_oid;
struct object_id *head = NULL, head_oid;
struct tree_desc desc[2] = { { NULL }, { NULL } };
struct lock_file lock = LOCK_INIT;
struct unpack_trees_options unpack_tree_opts = { 0 };
@ -26,8 +26,7 @@ int reset_head(struct repository *r, struct object_id *oid, const char *action,
const char *reflog_action;
struct strbuf msg = STRBUF_INIT;
size_t prefix_len;
struct object_id *orig = NULL, oid_orig,
*old_orig = NULL, oid_old_orig;
struct object_id *old_orig = NULL, oid_old_orig;
int ret = 0, nr = 0;
if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
@ -38,7 +37,9 @@ int reset_head(struct repository *r, struct object_id *oid, const char *action,
goto leave_reset_head;
}
if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
if (!get_oid("HEAD", &head_oid)) {
head = &head_oid;
} else if (!oid || !reset_hard) {
ret = error(_("could not determine HEAD revision"));
goto leave_reset_head;
}
@ -98,13 +99,12 @@ reset_head_refs:
if (update_orig_head) {
if (!get_oid("ORIG_HEAD", &oid_old_orig))
old_orig = &oid_old_orig;
if (!get_oid("HEAD", &oid_orig)) {
orig = &oid_orig;
if (head) {
if (!reflog_orig_head) {
strbuf_addstr(&msg, "updating ORIG_HEAD");
reflog_orig_head = msg.buf;
}
update_ref(reflog_orig_head, "ORIG_HEAD", orig,
update_ref(reflog_orig_head, "ORIG_HEAD", head,
old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
} else if (old_orig)
delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
@ -116,7 +116,7 @@ reset_head_refs:
reflog_head = msg.buf;
}
if (!switch_to_branch)
ret = update_ref(reflog_head, "HEAD", oid, orig,
ret = update_ref(reflog_head, "HEAD", oid, head,
detach_head ? REF_NO_DEREF : 0,
UPDATE_REFS_MSG_ON_ERR);
else {
@ -128,7 +128,7 @@ reset_head_refs:
}
if (run_hook)
run_hook_le(NULL, "post-checkout",
oid_to_hex(orig ? orig : null_oid()),
oid_to_hex(head ? head : null_oid()),
oid_to_hex(oid), "1", NULL);
leave_reset_head:

View File

@ -72,6 +72,19 @@ test_rebase () {
test_cmp_rev rebase-on-me $new &&
test $flag = 1
'
test_expect_success "rebase $args fast-forward branch checkout runs post-checkout hook" '
test_when_finished "test_might_fail git rebase --abort" &&
test_when_finished "rm -f .git/post-checkout.args" &&
git update-ref refs/heads/rebase-fast-forward three &&
git checkout two &&
rm -f .git/post-checkout.args &&
git rebase $args HEAD rebase-fast-forward &&
read old new flag <.git/post-checkout.args &&
test_cmp_rev two $old &&
test_cmp_rev three $new &&
test $flag = 1
'
}
test_rebase --apply &&