1 files changed, 67 insertions, 0 deletions
diff --git a/third_party/git/t/t6021-merge-criss-cross.sh b/third_party/git/t/t6021-merge-criss-cross.sh
new file mode 100755
index 000000000000..9d5e992878fa
--- /dev/null
+++ b/third_party/git/t/t6021-merge-criss-cross.sh
@@ -0,0 +1,67 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Fredrik Kuivinen
+#
+
+# See https://lore.kernel.org/git/Pine.LNX.4.44.0504271254120.4678-100000@wax.eds.org/ for a
+# nice description of what this is about.
+
+
+test_description='Test criss-cross merge'
+. ./test-lib.sh
+
+test_expect_success 'prepare repository' '
+	test_write_lines 1 2 3 4 5 6 7 8 9 >file &&
+	git add file &&
+	git commit -m "Initial commit" file &&
+
+	git branch A &&
+	git branch B &&
+	git checkout A &&
+
+	test_write_lines 1 2 3 4 5 6 7 "8 changed in B8, branch A" 9 >file &&
+	git commit -m "B8" file &&
+	git checkout B &&
+
+	test_write_lines 1 2 "3 changed in C3, branch B" 4 5 6 7 8 9 >file &&
+	git commit -m "C3" file &&
+	git branch C3 &&
+
+	git merge -m "pre E3 merge" A &&
+
+	test_write_lines 1 2 "3 changed in E3, branch B. New file size" 4 5 6 7 "8 changed in B8, branch A" 9 >file &&
+	git commit -m "E3" file &&
+
+	git checkout A &&
+	git merge -m "pre D8 merge" C3 &&
+	test_write_lines 1 2 "3 changed in C3, branch B" 4 5 6 7 "8 changed in D8, branch A. New file size 2" 9 >file &&
+
+	git commit -m D8 file
+'
+
+test_expect_success 'Criss-cross merge' '
+	git merge -m "final merge" B
+'
+
+test_expect_success 'Criss-cross merge result' '
+	cat <<-\EOF >file-expect &&
+	1
+	2
+	3 changed in E3, branch B. New file size
+	4
+	5
+	6
+	7
+	8 changed in D8, branch A. New file size 2
+	9
+	EOF
+
+	test_cmp file-expect file
+'
+
+test_expect_success 'Criss-cross merge fails (-s resolve)' '
+	git reset --hard A^ &&
+	test_must_fail git merge -s resolve -m "final merge" B
+'
+
+test_done