t4205: sort log output in a hash-independent way

This test enumerates log entries and then sorts them.  For SHA-1, this
produces results that happen to sort in the order specified in the test,
but for other hash algorithms they sort differently.  Ensure we sort the
log entries in a hash-independent way by sorting on the ref name instead
of the object ID.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4205-log-pretty-formats.sh

@@ -516,22 +516,22 @@ test_expect_success 'log decoration properly follows tag chain' '
 	git commit --amend -m shorter &&
 	git log --no-walk --tags --pretty="%H %d" --decorate=full >actual &&
 	cat <<-EOF >expected &&
-	$head1  (tag: refs/tags/tag2)
 	$head2  (tag: refs/tags/message-one)
 	$old_head1  (tag: refs/tags/message-two)
+	$head1  (tag: refs/tags/tag2)
 	EOF
-	sort actual >actual1 &&
+	sort -k3 actual >actual1 &&
 	test_cmp expected actual1
 '
 
 test_expect_success 'clean log decoration' '
 	git log --no-walk --tags --pretty="%H %D" --decorate=full >actual &&
 	cat >expected <<-EOF &&
-	$head1 tag: refs/tags/tag2
 	$head2 tag: refs/tags/message-one
 	$old_head1 tag: refs/tags/message-two
+	$head1 tag: refs/tags/tag2
 	EOF
-	sort actual >actual1 &&
+	sort -k3 actual >actual1 &&
 	test_cmp expected actual1
 '