[PATCH v2 5/8] t/lib-patch-mode.sh: fix ignored "git" exit codes

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Fix code added in b319ef70a94 (Add a small patch-mode testing library,
2009-08-13) to use &&-chaining and the newly added "test_cmp_cmd"
instead of interpolating "git" commands in a "test" statement.

This fixes cases where we'd have e.g. missed memory leaks under
SANITIZE=leak, this code doesn't leak now as far as I can tell, but I
discovered it while looking at leaks in related code.

The "cat _head >expect" here is redundant, we could simply give
"_head" to "test_cmp", but let's be consistent in using the "expect"
and "actual" names for clarity.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 t/lib-patch-mode.sh | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/t/lib-patch-mode.sh b/t/lib-patch-mode.sh
index cfd76bf987b..ae51f33a010 100644
--- a/t/lib-patch-mode.sh
+++ b/t/lib-patch-mode.sh
@@ -29,8 +29,11 @@ set_and_save_state () {
 
 # verify_state <path> <expected-worktree-content> <expected-index-content>
 verify_state () {
-	test "$(cat "$1")" = "$2" &&
-	test "$(git show :"$1")" = "$3"
+	echo "$2" >expect &&
+	cat "$1" >actual &&
+	test_cmp expect actual &&
+
+	test_cmp_cmd "$3" git show :"$1"
 }
 
 # verify_saved_state <path>
@@ -46,5 +49,5 @@ save_head () {
 }
 
 verify_saved_head () {
-	test "$(cat _head)" = "$(git rev-parse HEAD)"
+	test_cmp_cmd "$(cat _head)" git rev-parse HEAD
 }
-- 
2.39.0.rc1.980.g92d3d4579ad