[PATCH] Demonstrate breakage: checkout overwrites untracked symlink with directory

[Johannes Sixt <j6t@kdbg.org>]

This adds tests where an untracked file and an untracked symlink are in the
way where a directory should be created by 'git checkout'. Commit b1735b1a
(do not overwrite files in leading path, 2010-12-14) fixed the case where
a file is in the way, but the untracked symlink is still removed silently.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
---
On Mittwoch, 2. Februar 2011, Johannes Sixt wrote:
> It seems to interact with the lstat_cache. When lstat
> reports a symlink, this result is cached; but if it is a regular file, it
> is not cached.

The case where a file is in the way was fixed only in v1.7.3.4, but symlinks
are still affected. Clemens, can you help?

-- Hannes

PS: When a date is given for commit reference in a commit message as above,
do you prefer the author date or the committer date? Above, I took the
committer date, which is 2 months behind the author date.

 t/t2019-checkout-overwrite.sh |   50 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 50 insertions(+), 0 deletions(-)
 create mode 100755 t/t2019-checkout-overwrite.sh

diff --git a/t/t2019-checkout-overwrite.sh b/t/t2019-checkout-overwrite.sh
new file mode 100755
index 0000000..e4e529d
--- /dev/null
+++ b/t/t2019-checkout-overwrite.sh
@@ -0,0 +1,50 @@
+#!/bin/sh
+
+test_description='checkout must not overwrite an untracked objects'
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+
+	mkdir -p a/b/c &&
+	>a/b/c/d &&
+	git add -A &&
+	git commit -m base &&
+	git tag start
+'
+
+test_expect_success 'create a commit where dir a/b changed to file' '
+
+	git checkout -b file &&
+	rm -rf a/b &&
+	>a/b &&
+	git add -A &&
+	git commit -m "dir to file"
+'
+
+test_expect_success 'checkout commit with dir must not remove untracked a/b' '
+
+	git rm --cached a/b &&
+	git commit -m "un-track the file" &&
+	test_must_fail git checkout start &&
+	test -f a/b
+'
+
+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 &&
+	git commit -m "dir to symlink"
+'
+
+test_expect_failure '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 -h a/b
+'
+
+test_done
-- 
1.7.4.80.g89060