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

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

third_party/git/t/t6014-rev-list-all.sh

@@ -0,0 +1,42 @@
+#!/bin/sh
+
+test_description='--all includes detached HEADs'
+
+. ./test-lib.sh
+
+
+commit () {
+	test_tick &&
+	echo $1 > foo &&
+	git add foo &&
+	git commit -m "$1"
+}
+
+test_expect_success 'setup' '
+
+	commit one &&
+	commit two &&
+	git checkout HEAD^ &&
+	commit detached
+
+'
+
+test_expect_success 'rev-list --all lists detached HEAD' '
+
+	test 3 = $(git rev-list --all | wc -l)
+
+'
+
+test_expect_success 'repack does not lose detached HEAD' '
+
+	git gc &&
+	git prune --expire=now &&
+	git show HEAD
+
+'
+
+test_expect_success 'rev-list --graph --no-walk is forbidden' '
+	test_must_fail git rev-list --graph --no-walk HEAD
+'
+
+test_done