merge(third_party/git): Merge squashed git subtree at v2.23.0

Merge commit '1b593e1ea4' as 'third_party/git'

third_party/git/t/t7419-submodule-set-branch.sh

@@ -0,0 +1,93 @@
+#!/bin/sh
+#
+# Copyright (c) 2019 Denton Liu
+#
+
+test_description='Test submodules set-branch subcommand
+
+This test verifies that the set-branch subcommand of git-submodule is working
+as expected.
+'
+
+TEST_NO_CREATE_REPO=1
+. ./test-lib.sh
+
+test_expect_success 'submodule config cache setup' '
+	mkdir submodule &&
+	(cd submodule &&
+		git init &&
+		echo a >a &&
+		git add . &&
+		git commit -ma &&
+		git checkout -b topic &&
+		echo b >a &&
+		git add . &&
+		git commit -mb
+	) &&
+	mkdir super &&
+	(cd super &&
+		git init &&
+		git submodule add ../submodule &&
+		git commit -m "add submodule"
+	)
+'
+
+test_expect_success 'ensure submodule branch is unset' '
+	(cd super &&
+		test_must_fail grep branch .gitmodules
+	)
+'
+
+test_expect_success 'test submodule set-branch --branch' '
+	(cd super &&
+		git submodule set-branch --branch topic submodule &&
+		grep "branch = topic" .gitmodules &&
+		git submodule update --remote &&
+		cat <<-\EOF >expect &&
+		b
+		EOF
+		git -C submodule show -s --pretty=%s >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'test submodule set-branch --default' '
+	(cd super &&
+		git submodule set-branch --default submodule &&
+		test_must_fail grep branch .gitmodules &&
+		git submodule update --remote &&
+		cat <<-\EOF >expect &&
+		a
+		EOF
+		git -C submodule show -s --pretty=%s >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'test submodule set-branch -b' '
+	(cd super &&
+		git submodule set-branch -b topic submodule &&
+		grep "branch = topic" .gitmodules &&
+		git submodule update --remote &&
+		cat <<-\EOF >expect &&
+		b
+		EOF
+		git -C submodule show -s --pretty=%s >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_expect_success 'test submodule set-branch -d' '
+	(cd super &&
+		git submodule set-branch -d submodule &&
+		test_must_fail grep branch .gitmodules &&
+		git submodule update --remote &&
+		cat <<-\EOF >expect &&
+		a
+		EOF
+		git -C submodule show -s --pretty=%s >actual &&
+		test_cmp expect actual
+	)
+'
+
+test_done