test-lib: allow negation of prerequisites

diff --git a/t/t7501-commit.sh b/t/t7501-commit.sh
index 3f364a20e855f59e685dc424f51d93d7d7d8d7b9..195e7477d883f39d51f5740b5b309a489dd92d3d 100755 (executable)
--- a/t/t7501-commit.sh
+++ b/t/t7501-commit.sh
@@ -148,6 +148,21 @@ test_expect_success '--amend --edit' '
        test_cmp expect msg
 '
 
+test_expect_success '--amend --edit of empty message' '
+       cat >replace <<-\EOF &&
+       #!/bin/sh
+       echo "amended" >"$1"
+       EOF
+       chmod 755 replace &&
+       git commit --allow-empty --allow-empty-message -m "" &&
+       echo more bongo >file &&
+       git add file &&
+       EDITOR=./replace git commit --edit --amend &&
+       git diff-tree -s --format=%s HEAD >msg &&
+       ./replace expect &&
+       test_cmp expect msg
+'
+
 test_expect_success '-m --edit' '
        echo amended >expect &&
        git commit --allow-empty -m buffer &&