[PATCH] receive-pack: fix updateInstead with core.worktree

From: Alyssa Ross <hi@alyssa.is>
Date: May 22, 2026, 15:44 UTC
Message-ID: <20260522154418.5883-1-hi@alyssa.is>

This used to work, but when push_to_checkout() started being called before push_to_deploy(), push_to_checkout()'s side effect of adding GIT_WORK_TREE to the same environment that would be used by push_to_deploy() wasn't taken into account. Fix by only mutating the environment for push_to_commit(), rather than the shared environment.

Fixes: a8cc594333 ("hooks: fix an obscure TOCTOU "did we just run a hook?" race")
Signed-off-by: Alyssa Ross <hi@alyssa.is>
---
 builtin/receive-pack.c |  2 +-
 t/t5516-fetch-push.sh  | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index c7b2818f20..7ee157532d 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -1460,8 +1460,8 @@ static const char *push_to_checkout(unsigned char *hash,
 
 	opt.invoked_hook = invoked_hook;
 
-	strvec_pushf(env, "GIT_WORK_TREE=%s", absolute_path(work_tree));
 	strvec_pushv(&opt.env, env->v);
+	strvec_pushf(&opt.env, "GIT_WORK_TREE=%s", absolute_path(work_tree));
 	strvec_push(&opt.args, hash_to_hex(hash));
 	if (run_hooks_opt(the_repository, push_to_checkout_hook, &opt))
 		return "push-to-checkout hook declined";
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index 117cfa051f..f51fb11a6d 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1791,6 +1791,17 @@ test_expect_success 'updateInstead with push-to-checkout hook' '
 	)
 '
 
+test_expect_success 'denyCurrentBranch and core.worktree' '
+	test_when_finished "rm -fr cloned cloned.git" &&
+	git clone --separate-git-dir cloned.git . cloned &&
+	git --git-dir cloned.git config receive.denyCurrentBranch updateInstead &&
+	git --git-dir cloned.git config core.worktree "$PWD/cloned" &&
+        test_commit raspberry &&
+	git push cloned.git HEAD:main &&
+	test_path_exists cloned/raspberry.t &&
+	test_must_fail git push --delete cloned.git main
+'
+
 test_expect_success 'denyCurrentBranch and worktrees' '
 	test_when_finished "rm -fr cloned && git worktree remove --force new-wt" &&
 	git worktree add new-wt &&

base-commit: aec3f587505a472db67e9462d0702e7d463a449d

-- 
2.53.0