[PATCH 2/2] safe.directory: normalize the configured path

[Junio C Hamano <gitster@pobox.com>]

The pathname of a repository comes from getcwd() and it could be a
path aliased via symbolic links, e.g., the real directory may be
/home/u/repository but a symbolic link /home/u/repo may point at it,
and the clone request may come as "git clone file:///home/u/repo/"

A request to check if /home/u/repository is safe would be rejected
if the safe.directory configuration allows /home/u/repo/ but not its
alias /home/u/repository/.  Normalize the paths configured for the
safe.directory configuration variable before comparing them with the
path being checked.

Suggested-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 setup.c                   | 12 +++++++++++
 t/t0033-safe-directory.sh | 45 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/setup.c b/setup.c
index 45bbbe329f..29304d7452 100644
--- a/setup.c
+++ b/setup.c
@@ -1236,6 +1236,16 @@ static int safe_directory_cb(const char *key, const char *value,
 
 		if (!git_config_pathname(&allowed, key, value)) {
 			const char *check = allowed ? allowed : value;
+			char *to_free = real_pathdup(check, 0);
+
+			if (!to_free) {
+				warning(_("safe.directory '%s' cannot be normalized"),
+					check);
+				goto next;
+			} else {
+				check = to_free;
+			}
+
 			if (ends_with(check, "/*")) {
 				size_t len = strlen(check);
 				if (!fspathncmp(check, data->path, len - 1))
@@ -1243,7 +1253,9 @@ static int safe_directory_cb(const char *key, const char *value,
 			} else if (!fspathcmp(data->path, check)) {
 				data->is_safe = 1;
 			}
+			free(to_free);
 		}
+	next:
 		if (allowed != value)
 			free(allowed);
 	}
diff --git a/t/t0033-safe-directory.sh b/t/t0033-safe-directory.sh
index 3e487e7f4b..17d45d481e 100755
--- a/t/t0033-safe-directory.sh
+++ b/t/t0033-safe-directory.sh
@@ -164,4 +164,49 @@ test_expect_success SYMLINKS 'checked leading paths are normalized' '
 	git -C repo/s for-each-ref
 '
 
+test_expect_success SYMLINKS 'configured paths are normalized' '
+	test_when_finished "rm -rf repository; rm -f repo" &&
+	(
+		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
+		git config --global --unset-all safe.directory
+	) &&
+	git init repository &&
+	ln -s repository repo &&
+	(
+		cd repository &&
+		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
+		test_commit sample
+	) &&
+
+	(
+		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
+		git config --global safe.directory "$(pwd)/repo"
+	) &&
+	git -C repository/ for-each-ref >/dev/null &&
+	git -C repo/ for-each-ref
+'
+
+test_expect_success SYMLINKS 'configured leading paths are normalized' '
+	test_when_finished "rm -rf repository; rm -f repo" &&
+	(
+		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
+		git config --global --unset-all safe.directory
+	) &&
+	mkdir -p repository &&
+	git init repository/s &&
+	ln -s repository repo &&
+	(
+		cd repository &&
+		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
+		test_commit sample
+	) &&
+
+	(
+		sane_unset GIT_TEST_ASSUME_DIFFERENT_OWNER &&
+		git config --global safe.directory "$(pwd)/repo/*"
+	) &&
+	git -C repository/s for-each-ref >/dev/null &&
+	git -C repo/s for-each-ref
+'
+
 test_done
-- 
2.46.0-rc1-48-g0900f1888e