1 files changed, 76 insertions, 0 deletions
diff --git a/t/t2023-checkout-m.sh b/t/t2023-checkout-m.sh
new file mode 100755
index 0000000000..7b327b7544
--- /dev/null
+++ b/t/t2023-checkout-m.sh
@@ -0,0 +1,76 @@
+#!/bin/sh
+
+test_description='checkout -m -- <conflicted path>
+
+Ensures that checkout -m on a resolved file restores the conflicted file'
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+
+test_expect_success setup '
+	test_tick &&
+	test_commit both.txt both.txt initial &&
+	git branch topic &&
+	test_commit modified_in_main both.txt in_main &&
+	test_commit added_in_main each.txt in_main &&
+	git checkout topic &&
+	test_commit modified_in_topic both.txt in_topic &&
+	test_commit added_in_topic each.txt in_topic
+'
+
+test_expect_success 'git merge main' '
+    test_must_fail git merge main
+'
+
+clean_branchnames () {
+	# Remove branch names after conflict lines
+	sed 's/^\([<>]\{5,\}\) .*$/\1/'
+}
+
+test_expect_success '-m restores 2-way conflicted+resolved file' '
+	cp each.txt each.txt.conflicted &&
+	echo resolved >each.txt &&
+	git add each.txt &&
+	git checkout -m -- each.txt &&
+	clean_branchnames <each.txt >each.txt.cleaned &&
+	clean_branchnames <each.txt.conflicted >each.txt.conflicted.cleaned &&
+	test_cmp each.txt.conflicted.cleaned each.txt.cleaned
+'
+
+test_expect_success '-m restores 3-way conflicted+resolved file' '
+	cp both.txt both.txt.conflicted &&
+	echo resolved >both.txt &&
+	git add both.txt &&
+	git checkout -m -- both.txt &&
+	clean_branchnames <both.txt >both.txt.cleaned &&
+	clean_branchnames <both.txt.conflicted >both.txt.conflicted.cleaned &&
+	test_cmp both.txt.conflicted.cleaned both.txt.cleaned
+'
+
+test_expect_success 'force checkout a conflict file creates stage zero entry' '
+	git init co-force &&
+	(
+		cd co-force &&
+		echo a >a &&
+		git add a &&
+		git commit -ama &&
+		A_OBJ=$(git rev-parse :a) &&
+		git branch topic &&
+		echo b >a &&
+		git commit -amb &&
+		B_OBJ=$(git rev-parse :a) &&
+		git checkout topic &&
+		echo c >a &&
+		C_OBJ=$(git hash-object a) &&
+		git checkout -m main &&
+		test_cmp_rev :1:a $A_OBJ &&
+		test_cmp_rev :2:a $B_OBJ &&
+		test_cmp_rev :3:a $C_OBJ &&
+		git checkout -f topic &&
+		test_cmp_rev :0:a $A_OBJ
+	)
+'
+
+test_done