Add a testcase for ACL with restrictive umask.

Right now, Git creates unreadable pack files on non-shared
repositories when the user has a umask of 077, even when the default
ACLs for the directory would give read/write access to a specific
user.

Loose object files are created world-readable, which doesn't break ACLs,
but isn't necessarily desirable.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t1304-default-acl.sh

@@ -0,0 +1,67 @@
+#!/bin/sh
+#
+# Copyright (c) 2010 Matthieu Moy
+#
+
+test_description='Test repository with default ACL'
+
+# Create the test repo with restrictive umask
+# => this must come before . ./test-lib.sh
+umask 077
+
+. ./test-lib.sh
+
+# We need an arbitrary other user give permission to using ACLs. root
+# is a good candidate: exists on all unices, and it has permission
+# anyway, so we don't create a security hole running the testsuite.
+
+if ! setfacl -m u:root:rwx .; then
+    say "Skipping ACL tests: unable to use setfacl"
+    test_done
+fi
+
+modebits () {
+	ls -l "$1" | sed -e 's|^\(..........\).*|\1|'
+}
+
+check_perms_and_acl () {
+	actual=$(modebits "$1") &&
+	case "$actual" in
+	-r--r-----*)
+		: happy
+		;;
+	*)
+		echo "Got permission '$actual', expected '-r--r-----'"
+		false
+		;;
+	esac &&
+	getfacl "$1" > actual &&
+	grep -q "user:root:rwx" actual &&
+	grep -q "user:${LOGNAME}:rwx" actual &&
+	grep -q "mask::r--" actual &&
+	grep -q "group::---" actual || false
+}
+
+dirs_to_set="./ .git/ .git/objects/ .git/objects/pack/"
+
+test_expect_success 'Setup test repo' '
+	setfacl -m u:root:rwx          $dirs_to_set &&
+	setfacl -d -m u:"$LOGNAME":rwx $dirs_to_set &&
+	setfacl -d -m u:root:rwx       $dirs_to_set &&
+
+	touch file.txt &&
+	git add file.txt &&
+	git commit -m "init"
+'
+
+test_expect_failure 'Objects creation does not break ACLs with restrictive umask' '
+	# SHA1 for empty blob
+	check_perms_and_acl .git/objects/e6/9de29bb2d1d6434b8b29ae775ad8c2e48c5391
+'
+
+test_expect_failure 'git gc does not break ACLs with restrictive umask' '
+	git gc &&
+	check_perms_and_acl .git/objects/pack/*.pack
+'
+
+test_done