Sync with 2.39.4

* maint-2.39: (38 commits)
  Git 2.39.4
  fsck: warn about symlink pointing inside a gitdir
  core.hooksPath: add some protection while cloning
  init.templateDir: consider this config setting protected
  clone: prevent hooks from running during a clone
  Add a helper function to compare file contents
  init: refactor the template directory discovery into its own function
  find_hook(): refactor the `STRIP_EXTENSION` logic
  clone: when symbolic links collide with directories, keep the latter
  entry: report more colliding paths
  t5510: verify that D/F confusion cannot lead to an RCE
  submodule: require the submodule path to contain directories only
  clone_submodule: avoid using `access()` on directories
  submodules: submodule paths must not contain symlinks
  clone: prevent clashing git dirs when cloning submodule in parallel
  t7423: add tests for symlinked submodule directories
  has_dir_name(): do not get confused by characters < '/'
  docs: document security issues around untrusted .git dirs
  upload-pack: disable lazy-fetching by default
  fetch/clone: detect dubious ownership of local repositories
  ...

t/t5510-fetch.sh

@@ -1248,6 +1248,30 @@ EOF
 	test_cmp fatal-expect fatal-actual
 '
 
+test_expect_success SYMLINKS 'clone does not get confused by a D/F conflict' '
+	git init df-conflict &&
+	(
+		cd df-conflict &&
+		ln -s .git a &&
+		git add a &&
+		test_tick &&
+		git commit -m symlink &&
+		test_commit a- &&
+		rm a &&
+		mkdir -p a/hooks &&
+		write_script a/hooks/post-checkout <<-EOF &&
+		echo WHOOPSIE >&2
+		echo whoopsie >"$TRASH_DIRECTORY"/whoops
+		EOF
+		git add a/hooks/post-checkout &&
+		test_tick &&
+		git commit -m post-checkout
+	) &&
+	git clone df-conflict clone 2>err &&
+	! grep WHOOPS err &&
+	test_path_is_missing whoops
+'
+
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd