t0021: write "OUT <size>" only on success

"rot13-filter.pl" always writes "OUT <size>" to the debug log at the end
of a response.

This works perfectly for the existing responses "abort", "error", and
"success". A new response "delayed", that will be introduced in a
subsequent patch, accepts the input without giving the filtered result
right away. At this point we cannot know the size of the response.
Therefore, we do not write "OUT <size>" for "delayed" responses.

To simplify the code we do not write "OUT <size>" for "abort" and
"error" responses either as their size is always zero.

Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: larsxschneider

t/t0021-conversion.sh

@@ -588,7 +588,7 @@ test_expect_success PERL 'process filter should restart after unexpected write f
 		cat >expected.log <<-EOF &&
 			START
 			init handshake complete
-			IN: smudge smudge-write-fail.r $SF [OK] -- OUT: $SF [WRITE FAIL]
+			IN: smudge smudge-write-fail.r $SF [OK] -- [WRITE FAIL]
 			START
 			init handshake complete
 			IN: smudge test.r $S [OK] -- OUT: $S . [OK]
@@ -634,7 +634,7 @@ test_expect_success PERL 'process filter should not be restarted if it signals a
 		cat >expected.log <<-EOF &&
 			START
 			init handshake complete
-			IN: smudge error.r $SE [OK] -- OUT: 0 [ERROR]
+			IN: smudge error.r $SE [OK] -- [ERROR]
 			IN: smudge test.r $S [OK] -- OUT: $S . [OK]
 			IN: smudge test2.r $S2 [OK] -- OUT: $S2 . [OK]
 			STOP
@@ -673,7 +673,7 @@ test_expect_success PERL 'process filter abort stops processing of all further f
 		cat >expected.log <<-EOF &&
 			START
 			init handshake complete
-			IN: smudge abort.r $SA [OK] -- OUT: 0 [ABORT]
+			IN: smudge abort.r $SA [OK] -- [ABORT]
 			STOP
 		EOF
 		test_cmp_exclude_clean expected.log debug.log &&

t/t0021/rot13-filter.pl

@@ -153,9 +153,6 @@ sub packet_flush {
 		die "bad command '$command'";
 	}
 
-	print $debug "OUT: " . length($output) . " ";
-	$debug->flush();
-
 	if ( $pathname eq "error.r" ) {
 		print $debug "[ERROR]\n";
 		$debug->flush();
@@ -178,6 +175,9 @@ sub packet_flush {
 			die "${command} write error";
 		}
 
+		print $debug "OUT: " . length($output) . " ";
+		$debug->flush();
+
 		while ( length($output) > 0 ) {
 			my $packet = substr( $output, 0, $MAX_PACKET_CONTENT_SIZE );
 			packet_bin_write($packet);