[PATCH] Add test that checkout does not overwrite entries in .git/info/exclude

[Johannes Sixt <j.sixt@viscovery.net>]

From: Johannes Sixt <j6t@kdbg.org>

It is an unintended accident that entries matched by .git/info/exclude are
considered precious, but entries matched by .gitignore are not. That is,
'git checkout' will overwrite untracked files matched by .gitignore, but
refuses to overwrite files matched by .git/info/exclude.

It is a lucky accident: it allows the distinction between "untracked but
precious" and "untracked and garbage". And it is a doubly lucky accident:
.gitignore entries are meant for files like build products, which usually
affect all consumers of a repository, whereas .git/info/exclude is
intended for personal files, which frequently are precious (think of a
TODO file).

Add a test that codifies the accident as wanted behavior.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
---
Am 11/21/2011 4:36, schrieb Junio C Hamano:
> As far as I am aware, info/exclude should work exactly the same as having
> a .gitignore file at the root level of the working tree. Can you show a
> minimum reproduction recipe in a form of a patch to our test scripts in t/
> hierarchy?

Here you are. As you can see from my commit message, IMO, this is
a very useful accident. Therefore, there is no 'test_expect_failure'
in the test script :-)

-- Hannes

 t/t2023-checkout-ignored.sh |   51 +++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 51 insertions(+), 0 deletions(-)
 create mode 100755 t/t2023-checkout-ignored.sh

diff --git a/t/t2023-checkout-ignored.sh b/t/t2023-checkout-ignored.sh
new file mode 100755
index 0000000..03a5a56
--- /dev/null
+++ b/t/t2023-checkout-ignored.sh
@@ -0,0 +1,51 @@
+#!/bin/sh
+
+test_description='checkout overwrites or preserves ignored files
+
+`git checkout` makes a distinction between files mentioned in
+.gitignore and .git/info/exclude in that untracked files matched
+by the latter are considered precious and are not overwritten.
+'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+
+	echo excluded > excluded &&
+	echo ignored > ignored &&
+	git add . &&
+	test_commit initial &&
+	git checkout -b side &&
+	git rm excluded &&
+	git mv ignored .gitignore &&
+	test_commit side &&
+	echo excluded >> .git/info/exclude
+'
+
+test_expect_success 'files are ignored' '
+
+	echo keep > excluded &&
+	echo overwrite > ignored &&
+	list=$(git ls-files --others --exclude-standard) &&
+	test -z "$list"
+'
+
+test_expect_success 'entries in .git/info/exclude are precious' '
+
+	test_must_fail git checkout master 2>errors &&
+	test_i18ngrep "would be overwritten" errors &&
+	grep "	excluded" errors &&
+	! grep "	ignored" errors &&
+	grep keep excluded &&
+	grep overwrite ignored
+'
+
+test_expect_success 'entries in .gitignore are not precious' '
+
+	rm -f excluded &&
+	git checkout master &&
+	grep excluded excluded &&
+	grep ignored ignored
+'
+
+test_done
-- 
1.7.8.rc0.126.gd15506