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

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

third_party/git/t/t3505-cherry-pick-empty.sh

@@ -0,0 +1,99 @@
+#!/bin/sh
+
+test_description='test cherry-picking an empty commit'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+
+	echo first > file1 &&
+	git add file1 &&
+	test_tick &&
+	git commit -m "first" &&
+
+	git checkout -b empty-message-branch &&
+	echo third >> file1 &&
+	git add file1 &&
+	test_tick &&
+	git commit --allow-empty-message -m "" &&
+
+	git checkout master &&
+	git checkout -b empty-change-branch &&
+	test_tick &&
+	git commit --allow-empty -m "empty"
+
+'
+
+test_expect_success 'cherry-pick an empty commit' '
+	git checkout master &&
+	test_expect_code 1 git cherry-pick empty-change-branch
+'
+
+test_expect_success 'index lockfile was removed' '
+	test ! -f .git/index.lock
+'
+
+test_expect_success 'cherry-pick a commit with an empty message' '
+	test_when_finished "git reset --hard empty-message-branch~1" &&
+	git checkout master &&
+	git cherry-pick empty-message-branch
+'
+
+test_expect_success 'index lockfile was removed' '
+	test ! -f .git/index.lock
+'
+
+test_expect_success 'cherry-pick a commit with an empty message with --allow-empty-message' '
+	git checkout -f master &&
+	git cherry-pick --allow-empty-message empty-message-branch
+'
+
+test_expect_success 'cherry pick an empty non-ff commit without --allow-empty' '
+	git checkout master &&
+	echo fourth >>file2 &&
+	git add file2 &&
+	git commit -m "fourth" &&
+	test_must_fail git cherry-pick empty-change-branch
+'
+
+test_expect_success 'cherry pick an empty non-ff commit with --allow-empty' '
+	git checkout master &&
+	git cherry-pick --allow-empty empty-change-branch
+'
+
+test_expect_success 'cherry pick with --keep-redundant-commits' '
+	git checkout master &&
+	git cherry-pick --keep-redundant-commits HEAD^
+'
+
+test_expect_success 'cherry-pick a commit that becomes no-op (prep)' '
+	git checkout master &&
+	git branch fork &&
+	echo foo >file2 &&
+	git add file2 &&
+	test_tick &&
+	git commit -m "add file2 on master" &&
+
+	git checkout fork &&
+	echo foo >file2 &&
+	git add file2 &&
+	test_tick &&
+	git commit -m "add file2 on the side"
+'
+
+test_expect_success 'cherry-pick a no-op without --keep-redundant' '
+	git reset --hard &&
+	git checkout fork^0 &&
+	test_must_fail git cherry-pick master
+'
+
+test_expect_success 'cherry-pick a no-op with --keep-redundant' '
+	git reset --hard &&
+	git checkout fork^0 &&
+	git cherry-pick --keep-redundant-commits master &&
+	git show -s --format=%s >actual &&
+	echo "add file2 on master" >expect &&
+	test_cmp expect actual
+'
+
+test_done