From 2aebae7aff41a68c514561009c7df29e176b8571 Mon Sep 17 00:00:00 2001
From: Sven van Heugten <sven@memcmp.org>
Date: Fri, 6 Mar 2026 04:24:20 +0100
Subject: [PATCH] Add test where replacement removes entire line

```git-check-assertions
run test/mechanicaldiff.bats
assert_success

git checkout HEAD~2 bin
run test/mechanicaldiff.bats
assert_failure
assert_output --partial "-- command failed --"
```
---
 test/mechanicaldiff.bats | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/test/mechanicaldiff.bats b/test/mechanicaldiff.bats
index d5c2748..acefc62 100755
--- a/test/mechanicaldiff.bats
+++ b/test/mechanicaldiff.bats
@@ -143,6 +143,25 @@ setup() {
   assert_output "$(cat "$BATS_TEST_TMPDIR/diff")"
 }
 
+@test "matches when replacement removes entire line" {
+  cat >"$BATS_TEST_TMPDIR/old" <<-'EOF'
+	alpha
+	foo
+	omega
+	EOF
+  cat >"$BATS_TEST_TMPDIR/new" <<-'EOF'
+	alpha
+	omega
+	EOF
+
+  git diff --no-index "$BATS_TEST_TMPDIR/old" "$BATS_TEST_TMPDIR/new" \
+    >"$BATS_TEST_TMPDIR/diff" || true
+
+  run mechanicaldiff.py foo "" <"$BATS_TEST_TMPDIR/diff"
+  assert_success
+  assert_output "$(cat "$BATS_TEST_TMPDIR/diff")"
+}
+
 @test "ignores leading and trailing blank lines for comparison" {
   cat >"$BATS_TEST_TMPDIR/old" <<-'EOF'