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

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

third_party/git/t/t1505-rev-parse-last.sh

@@ -0,0 +1,61 @@
+#!/bin/sh
+
+test_description='test @{-N} syntax'
+
+. ./test-lib.sh
+
+
+make_commit () {
+	echo "$1" > "$1" &&
+	git add "$1" &&
+	git commit -m "$1"
+}
+
+
+test_expect_success 'setup' '
+
+	make_commit 1 &&
+	git branch side &&
+	make_commit 2 &&
+	make_commit 3 &&
+	git checkout side &&
+	make_commit 4 &&
+	git merge master &&
+	git checkout master
+
+'
+
+# 1 -- 2 -- 3 master
+#  \         \
+#   \         \
+#    --- 4 --- 5 side
+#
+# and 'side' should be the last branch
+
+test_expect_success '@{-1} works' '
+	test_cmp_rev side @{-1}
+'
+
+test_expect_success '@{-1}~2 works' '
+	test_cmp_rev side~2 @{-1}~2
+'
+
+test_expect_success '@{-1}^2 works' '
+	test_cmp_rev side^2 @{-1}^2
+'
+
+test_expect_success '@{-1}@{1} works' '
+	test_cmp_rev side@{1} @{-1}@{1}
+'
+
+test_expect_success '@{-2} works' '
+	test_cmp_rev master @{-2}
+'
+
+test_expect_success '@{-3} fails' '
+	test_must_fail git rev-parse @{-3}
+'
+
+test_done
+
+