From c95ab83c16c8d993499ebb6e4802c464e6341ce2 Mon Sep 17 00:00:00 2001
From: echobt <154886644+echobt@users.noreply.github.com>
Date: Sat, 19 Sep 2026 23:00:02 +0000
Subject: [PATCH] fix(hooks): isolate fixture git context before push

---
 .githooks/pre-push      |  2 ++
 tests/test_git_hooks.py | 59 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100644 tests/test_git_hooks.py

diff --git a/.githooks/pre-push b/.githooks/pre-push
index fca179c55..15f1ee7fc 100755
--- a/.githooks/pre-push
+++ b/.githooks/pre-push
@@ -3,6 +3,8 @@
 set -euo pipefail
 root="$(git rev-parse --show-toplevel)"
 cd "$root"
+# Tests create foreign repositories; discard this worktree's inherited Git context.
+unset $(git rev-parse --local-env-vars)
 if ! command -v uv >/dev/null 2>&1; then
   echo "pre-push: uv is required" >&2
   exit 1
diff --git a/tests/test_git_hooks.py b/tests/test_git_hooks.py
new file mode 100644
index 000000000..97a4c1405
--- /dev/null
+++ b/tests/test_git_hooks.py
@@ -0,0 +1,59 @@
+"""Local Git hooks isolate fixture repositories from the checkout being pushed."""
+
+import os
+import shutil
+import subprocess
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def test_pre_push_fixture_git_preserves_linked_repository_and_staged_changes(tmp_path):
+    main = tmp_path / "main"
+    linked = tmp_path / "linked"
+    remote = tmp_path / "remote.git"
+    fixture = tmp_path / "fixture"
+    env = {key: value for key, value in os.environ.items() if not key.startswith("GIT_")}
+    env.update(
+        GIT_CONFIG_NOSYSTEM="1",
+        GIT_CONFIG_GLOBAL=os.devnull,
+        PATH=f"{tmp_path / 'bin'}{os.pathsep}{env['PATH']}",
+        CORTEX_HOOK_TEST_FIXTURE=str(fixture),
+    )
+
+    def git(*args):
+        return subprocess.run(
+            ["git", *map(str, args)], env=env, check=True, capture_output=True, text=True
+        ).stdout.strip()
+
+    git("init", "-q", main)
+    git("-C", main, "config", "user.name", "Hook test")
+    git("-C", main, "config", "user.email", "hook@example.test")
+    git("-C", main, "commit", "-q", "--allow-empty", "-m", "initial")
+    git("-C", main, "worktree", "add", "-q", "-b", "topic", linked)
+    git("init", "-q", "--bare", remote)
+    (linked / "pending.txt").write_text("preserve this staged change")
+    git("-C", linked, "add", "pending.txt")
+    index_tree = git("-C", linked, "write-tree")
+    config = (main / ".git/config").read_bytes()
+    shutil.copy2(ROOT / ".githooks/pre-push", main / ".git/hooks/pre-push")
+    # Stand in for the test runner; Git and the repository's push hook remain real.
+    runner = tmp_path / "bin/uv"
+    runner.parent.mkdir()
+    runner.write_text(
+        '#!/bin/sh\nset -eu\n[ "$3" = pytest ] || exit 0\n'
+        'git init -q "$CORTEX_HOOK_TEST_FIXTURE"\n'
+        'printf fixture > "$CORTEX_HOOK_TEST_FIXTURE/fixture.txt"\n'
+        'git -C "$CORTEX_HOOK_TEST_FIXTURE" add fixture.txt\n',
+    )
+    runner.chmod(0o755)
+
+    git("-C", linked, "push", str(remote), "topic")
+
+    assert (fixture / ".git").is_dir()
+    assert (main / ".git/config").read_bytes() == config
+    assert git("-C", main, "rev-parse", "--show-toplevel") == str(main.resolve())
+    assert git("-C", main, "status", "--porcelain") == ""
+    assert git("-C", linked, "write-tree") == index_tree
+    assert git("-C", fixture, "diff", "--cached", "--name-only") == "fixture.txt"
+    assert git("--git-dir", remote, "rev-parse", "topic") == git("-C", linked, "rev-parse", "HEAD")