t7003-filter-branch: Fix test of a failing --msg-filter.

diff --git a/t/t7500-commit.sh b/t/t7500-commit.sh
index f11ada8617d95e2c3840ed1ecbdb03745d1f6f2b..26bd8ee469ad5bad5e4e9700c490cb3e3cb73b83 100755 (executable)
--- a/t/t7500-commit.sh
+++ b/t/t7500-commit.sh
@@ -93,4 +93,36 @@ test_expect_success 'commit message from file should override template' '
        commit_msg_is "standard input msg<unknown>"
 '
 
+test_expect_success 'using alternate GIT_INDEX_FILE (1)' '
+
+       cp .git/index saved-index &&
+       (
+               echo some new content >file &&
+               GIT_INDEX_FILE=.git/another_index &&
+               export GIT_INDEX_FILE &&
+               git add file &&
+               git commit -m "commit using another index" &&
+               git diff-index --exit-code HEAD &&
+               git diff-files --exit-code
+       ) &&
+       cmp .git/index saved-index >/dev/null
+
+'
+
+test_expect_success 'using alternate GIT_INDEX_FILE (2)' '
+
+       cp .git/index saved-index &&
+       (
+               rm -f .git/no-such-index &&
+               GIT_INDEX_FILE=.git/no-such-index &&
+               export GIT_INDEX_FILE &&
+               git commit -m "commit using nonexistent index" &&
+               test -z "$(git ls-files)" &&
+               test -z "$(git ls-tree HEAD)"
+
+       ) &&
+       cmp .git/index saved-index >/dev/null
+
+'
+
 test_done