reflog tests: add --updateref tests

Add tests that cover blindspots in "git reflog delete --updateref"
behavior. Before this change removing the "type & REF_ISSYMREF" check
added in 5e6f003 (reflog_expire(): ignore --updateref for symbolic
references, 2015-03-03) would not fail any tests.

The "--updateref" option was added in 55f1056 (git-reflog: add
option --updateref to write the last reflog sha1 into the ref,
2008-02-22) for use in git-stash.sh, see e25d5f9 (git-stash: add
new 'drop' subcommand, 2008-02-22).

Even though the regression test I need is just the "C" case here,
let's test all these combinations for good measure. I started out
doing these as a for-loop, but I think this is more readable.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: avar

t/t1417-reflog-updateref.sh

@@ -0,0 +1,65 @@
+#!/bin/sh
+
+test_description='git reflog --updateref'
+
+TEST_PASSES_SANITIZE_LEAK=true
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	git init -b main repo &&
+	(
+		cd repo &&
+
+		test_commit A &&
+		test_commit B &&
+		test_commit C &&
+
+		cp .git/logs/HEAD HEAD.old &&
+		git reset --hard HEAD~ &&
+		cp HEAD.old .git/logs/HEAD
+	)
+'
+
+test_reflog_updateref () {
+	exp=$1
+	shift
+	args="$@"
+
+	test_expect_success REFFILES "get '$exp' with '$args'"  '
+		test_when_finished "rm -rf copy" &&
+		cp -R repo copy &&
+
+		(
+			cd copy &&
+
+			$args &&
+			git rev-parse $exp >expect &&
+			git rev-parse HEAD >actual &&
+
+			test_cmp expect actual
+		)
+	'
+}
+
+test_reflog_updateref B git reflog delete --updateref HEAD@{0}
+test_reflog_updateref B git reflog delete --updateref HEAD@{1}
+test_reflog_updateref C git reflog delete --updateref main@{0}
+test_reflog_updateref B git reflog delete --updateref main@{1}
+test_reflog_updateref B git reflog delete --updateref --rewrite HEAD@{0}
+test_reflog_updateref B git reflog delete --updateref --rewrite HEAD@{1}
+test_reflog_updateref C git reflog delete --updateref --rewrite main@{0}
+test_reflog_updateref B git reflog delete --updateref --rewrite main@{1}
+test_reflog_updateref B test_must_fail git reflog expire  HEAD@{0}
+test_reflog_updateref B test_must_fail git reflog expire  HEAD@{1}
+test_reflog_updateref B test_must_fail git reflog expire  main@{0}
+test_reflog_updateref B test_must_fail git reflog expire  main@{1}
+test_reflog_updateref B test_must_fail git reflog expire --updateref HEAD@{0}
+test_reflog_updateref B test_must_fail git reflog expire --updateref HEAD@{1}
+test_reflog_updateref B test_must_fail git reflog expire --updateref main@{0}
+test_reflog_updateref B test_must_fail git reflog expire --updateref main@{1}
+test_reflog_updateref B test_must_fail git reflog expire --updateref --rewrite HEAD@{0}
+test_reflog_updateref B test_must_fail git reflog expire --updateref --rewrite HEAD@{1}
+test_reflog_updateref B test_must_fail git reflog expire --updateref --rewrite main@{0}
+test_reflog_updateref B test_must_fail git reflog expire --updateref --rewrite main@{1}
+
+test_done