t1450: make sure fsck detects a malformed tagger line

With "hash-object --literally", write a tag object that is not
supposed to pass one of the new checks added to "fsck", and make
sure that the new check catches the breakage.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t1450-fsck.sh

@@ -213,6 +213,25 @@ test_expect_success 'tag with incorrect tag name & missing tagger' '
 	grep "expected .tagger. line" out
 '
 
+test_expect_success 'tag with bad tagger' '
+	sha=$(git rev-parse HEAD) &&
+	cat >wrong-tag <<-EOF &&
+	object $sha
+	type commit
+	tag not-quite-wrong
+	tagger Bad Tagger Name
+
+	This is an invalid tag.
+	EOF
+
+	tag=$(git hash-object --literally -t tag -w --stdin <wrong-tag) &&
+	test_when_finished "remove_object $tag" &&
+	echo $tag >.git/refs/tags/wrong &&
+	test_when_finished "git update-ref -d refs/tags/wrong" &&
+	test_must_fail git fsck --tags 2>out &&
+	grep "error in tag .*: invalid author/committer" out
+'
+
 test_expect_success 'cleaned up' '
 	git fsck >actual 2>&1 &&
 	test_cmp empty actual