Rework partial packet handling once more

Address the concern that commit c53c2fec raised differently.

The original direction of the traffic is encoded in bit 0
of the flight number.
Reviewed-by: NAndy Polyakov <appro@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5923)

util/perl/TLSProxy/Proxy.pm

@@ -479,7 +479,7 @@ sub process_packet
 
     print "\n";
 
-    if (scalar(@{$ret[0]}) == 0) {
+    if (scalar(@{$ret[0]}) == 0 or length($ret[2]) != 0) {
         return "";
     }
 

util/perl/TLSProxy/Record.pm

@@ -279,7 +279,8 @@ sub reconstruct_record
     my $server = shift;
     my $data;
 
-    if ($self->{sent}) {
+    #We only replay the records in the same direction
+    if ($self->{sent} || ($self->flight & 1) != $server) {
         return "";
     }
     $self->{sent} = 1;