1 files changed, 164 insertions, 0 deletions
diff --git a/third_party/git/t/t7603-merge-reduce-heads.sh b/third_party/git/t/t7603-merge-reduce-heads.sh
new file mode 100755
index 000000000000..98948955ae50
--- /dev/null
+++ b/third_party/git/t/t7603-merge-reduce-heads.sh
@@ -0,0 +1,164 @@
+#!/bin/sh
+
+test_description='git merge
+
+Testing octopus merge when reducing parents to independent branches.'
+
+. ./test-lib.sh
+
+# 0 - 1
+#   \ 2
+#   \ 3
+#   \ 4 - 5
+#
+# So 1, 2, 3 and 5 should be kept, 4 should be avoided.
+
+test_expect_success 'setup' '
+	echo c0 > c0.c &&
+	git add c0.c &&
+	git commit -m c0 &&
+	git tag c0 &&
+	echo c1 > c1.c &&
+	git add c1.c &&
+	git commit -m c1 &&
+	git tag c1 &&
+	git reset --hard c0 &&
+	echo c2 > c2.c &&
+	git add c2.c &&
+	git commit -m c2 &&
+	git tag c2 &&
+	git reset --hard c0 &&
+	echo c3 > c3.c &&
+	git add c3.c &&
+	git commit -m c3 &&
+	git tag c3 &&
+	git reset --hard c0 &&
+	echo c4 > c4.c &&
+	git add c4.c &&
+	git commit -m c4 &&
+	git tag c4 &&
+	echo c5 > c5.c &&
+	git add c5.c &&
+	git commit -m c5 &&
+	git tag c5
+'
+
+test_expect_success 'merge c1 with c2, c3, c4, c5' '
+	git reset --hard c1 &&
+	git merge c2 c3 c4 c5 &&
+	test "$(git rev-parse c1)" != "$(git rev-parse HEAD)" &&
+	test "$(git rev-parse c1)" = "$(git rev-parse HEAD^1)" &&
+	test "$(git rev-parse c2)" = "$(git rev-parse HEAD^2)" &&
+	test "$(git rev-parse c3)" = "$(git rev-parse HEAD^3)" &&
+	test "$(git rev-parse c5)" = "$(git rev-parse HEAD^4)" &&
+	git diff --exit-code &&
+	test -f c0.c &&
+	test -f c1.c &&
+	test -f c2.c &&
+	test -f c3.c &&
+	test -f c4.c &&
+	test -f c5.c &&
+	git show --format=%s -s >actual &&
+	! grep c1 actual &&
+	grep c2 actual &&
+	grep c3 actual &&
+	! grep c4 actual &&
+	grep c5 actual
+'
+
+test_expect_success 'pull c2, c3, c4, c5 into c1' '
+	git reset --hard c1 &&
+	git pull . c2 c3 c4 c5 &&
+	test "$(git rev-parse c1)" != "$(git rev-parse HEAD)" &&
+	test "$(git rev-parse c1)" = "$(git rev-parse HEAD^1)" &&
+	test "$(git rev-parse c2)" = "$(git rev-parse HEAD^2)" &&
+	test "$(git rev-parse c3)" = "$(git rev-parse HEAD^3)" &&
+	test "$(git rev-parse c5)" = "$(git rev-parse HEAD^4)" &&
+	git diff --exit-code &&
+	test -f c0.c &&
+	test -f c1.c &&
+	test -f c2.c &&
+	test -f c3.c &&
+	test -f c4.c &&
+	test -f c5.c &&
+	git show --format=%s -s >actual &&
+	! grep c1 actual &&
+	grep c2 actual &&
+	grep c3 actual &&
+	! grep c4 actual &&
+	grep c5 actual
+'
+
+test_expect_success 'setup' '
+	for i in A B C D E
+	do
+		echo $i > $i.c &&
+		git add $i.c &&
+		git commit -m $i &&
+		git tag $i
+	done &&
+	git reset --hard A &&
+	for i in F G H I
+	do
+		echo $i > $i.c &&
+		git add $i.c &&
+		git commit -m $i &&
+		git tag $i
+	done
+'
+
+test_expect_success 'merge E and I' '
+	git reset --hard A &&
+	git merge E I
+'
+
+test_expect_success 'verify merge result' '
+	test $(git rev-parse HEAD^1) = $(git rev-parse E) &&
+	test $(git rev-parse HEAD^2) = $(git rev-parse I)
+'
+
+test_expect_success 'add conflicts' '
+	git reset --hard E &&
+	echo foo > file.c &&
+	git add file.c &&
+	git commit -m E2 &&
+	git tag E2 &&
+	git reset --hard I &&
+	echo bar >file.c &&
+	git add file.c &&
+	git commit -m I2 &&
+	git tag I2
+'
+
+test_expect_success 'merge E2 and I2, causing a conflict and resolve it' '
+	git reset --hard A &&
+	test_must_fail git merge E2 I2 &&
+	echo baz > file.c &&
+	git add file.c &&
+	git commit -m "resolve conflict"
+'
+
+test_expect_success 'verify merge result' '
+	test $(git rev-parse HEAD^1) = $(git rev-parse E2) &&
+	test $(git rev-parse HEAD^2) = $(git rev-parse I2)
+'
+
+test_expect_success 'fast-forward to redundant refs' '
+	git reset --hard c0 &&
+	git merge c4 c5
+'
+
+test_expect_success 'verify merge result' '
+	test $(git rev-parse HEAD) = $(git rev-parse c5)
+'
+
+test_expect_success 'merge up-to-date redundant refs' '
+	git reset --hard c5 &&
+	git merge c0 c4
+'
+
+test_expect_success 'verify merge result' '
+	test $(git rev-parse HEAD) = $(git rev-parse c5)
+'
+
+test_done