tests: use test_ln_s_add to remove SYMLINKS prerequisite (trivial cases)

There are many instances where the treatment of symbolic links in the
object model and the algorithms are tested, but where it is not
necessary to actually have a symbolic link in the worktree. Make
adjustments to the tests and remove the SYMLINKS prerequisite when
appropriate in trivial cases, where "trivial" means:

- merely a replacement of 'ln -s a b && git add b' by test_ln_s_add
  is needed;

- a test for symbolic link on the file system can be split off (and
  remains protected by SYMLINKS);

- existing code is equivalent to test_ln_s_add.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/t/t2021-checkout-overwrite.sh b/t/t2021-checkout-overwrite.sh
index 5da63e9..c2ada7d 100755
--- a/t/t2021-checkout-overwrite.sh
+++ b/t/t2021-checkout-overwrite.sh
@@ -29,21 +29,25 @@ test_expect_success 'checkout commit with dir must not remove untracked a/b' '
 	test -f a/b
 '
 
-test_expect_success SYMLINKS 'create a commit where dir a/b changed to symlink' '
+test_expect_success 'create a commit where dir a/b changed to symlink' '
 
 	rm -rf a/b &&	# cleanup if previous test failed
 	git checkout -f -b symlink start &&
 	rm -rf a/b &&
-	ln -s foo a/b &&
 	git add -A &&
+	test_ln_s_add foo a/b &&
 	git commit -m "dir to symlink"
 '
 
-test_expect_success SYMLINKS 'checkout commit with dir must not remove untracked a/b' '
+test_expect_success 'checkout commit with dir must not remove untracked a/b' '
 
 	git rm --cached a/b &&
 	git commit -m "un-track the symlink" &&
-	test_must_fail git checkout start &&
+	test_must_fail git checkout start
+'
+
+test_expect_success SYMLINKS 'the symlink remained' '
+
 	test -h a/b
 '