[PATCH] do not overwrite untracked symlinks

[Clemens Buchacher <drizzd@aon.at>]

Git traditionally overwrites untracked symlinks silently. This will
generally not cause massive data loss, but it is inconsistent with
the behavior for regular files, which are not silently overwritten.

With this change, git refuses to overwrite untracked symlinks by
default. If the user really wants to overwrite the untracked
symlink, he has git-clean and git-checkout -f at his disposal.

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
---

I checked and there are no undesireable side-effects. One test had
to be modified slightly because it does overwrite an untracked
symlink.

 symlinks.c                      |    2 +-
 t/t6035-merge-dir-to-symlink.sh |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/symlinks.c b/symlinks.c
index 3cacebd..034943b 100644
--- a/symlinks.c
+++ b/symlinks.c
@@ -223,7 +223,7 @@ int check_leading_path(const char *name, int len)
 	int flags;
 	int match_len = lstat_cache_matchlen(cache, name, len, &flags,
 			   FL_SYMLINK|FL_NOENT|FL_DIR, USE_ONLY_LSTAT);
-	if (flags & (FL_SYMLINK|FL_NOENT))
+	if (flags & FL_NOENT)
 		return 0;
 	else if (flags & FL_DIR)
 		return -1;
diff --git a/t/t6035-merge-dir-to-symlink.sh b/t/t6035-merge-dir-to-symlink.sh
index 92e02d5..1de285b 100755
--- a/t/t6035-merge-dir-to-symlink.sh
+++ b/t/t6035-merge-dir-to-symlink.sh
@@ -22,7 +22,7 @@ test_expect_success SYMLINKS 'keep a/b-2/c/d across checkout' '
 	git reset --hard master &&
 	git rm --cached a/b &&
 	git commit -m "untracked symlink remains" &&
-	 git checkout start^0 &&
+	 git checkout -f start^0 &&
 	 test -f a/b-2/c/d
 '
 
-- 
1.7.3.1.105.g84915