[Outreachy PATCH 2/2] t0410: keep git's exit code in test_grep calls

[Dorine Tipo <dorine.a.tipo@gmail.com>]

The 'rev-list stops traversal at missing and promised tree' test passes
"$(git -C repo rev-parse ...)" directly to test_grep. t/README says
not to use command substitution in a way that discards git's exit
code: the && chain only sees test_grep's exit code, so a failure in
git is not caught there.

Assign the rev-parse output to variables first and pass those to
test_grep instead.

Signed-off-by: Dorine Tipo <dorine.a.tipo@gmail.com>
---
 t/t0410-partial-clone.sh | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index a24b663f73..57da830105 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -413,9 +413,13 @@ test_expect_success 'rev-list stops traversal at missing and promised tree' '
 	git -C repo config core.repositoryformatversion 1 &&
 	git -C repo config extensions.partialclone "arbitrary string" &&
 	git -C repo rev-list --exclude-promisor-objects --objects HEAD >out &&
-	test_grep $(git -C repo rev-parse foo) out &&
+
+	FOO=$(git -C repo rev-parse foo) &&
+	HEAD_OID=$(git -C repo rev-parse HEAD) &&
+
+	test_grep "$FOO" out &&
 	test_grep ! $TREE out &&
-	test_grep $(git -C repo rev-parse HEAD) out &&
+	test_grep "$HEAD_OID" out &&
 	test_grep ! $TREE2 out
 '
 
-- 
2.34.1