Fix #393: ensure proper reuse of existing multicast T->O connection

When a master scanner, or standby input-only scanner, reconnects after
having lost its connection (extended link loss or simply closed conn.)
we must reuse the full state of an existing connection to ensure that
we do not cause a disruption in existing data flows.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

source/src/cip/cipioconnection.c

@@ -526,15 +526,13 @@ EipStatus OpenProducingMulticastConnection(
       kEipInvalidSocket;
   }
 
-  common_packet_format_data->address_info_item[j].length = 16;
+  memcpy(&connection_object->remote_address, &existing_connection_object->remote_address, sizeof(connection_object->remote_address));
+  connection_object->eip_level_sequence_count_producing = existing_connection_object->eip_level_sequence_count_producing;
+  connection_object->sequence_count_producing = existing_connection_object->sequence_count_producing;
+  connection_object->transmission_trigger_timer = existing_connection_object->transmission_trigger_timer;
 
-  connection_object->remote_address.sin_family = AF_INET;
-  connection_object->remote_address.sin_port =
-    common_packet_format_data->address_info_item[j].sin_port = port;
-  connection_object->remote_address.sin_addr.s_addr =
-    common_packet_format_data->address_info_item[j].sin_addr =
-      g_tcpip.mcast_config.starting_multicast_address;
   memset(common_packet_format_data->address_info_item[j].nasin_zero, 0, 8);
+  common_packet_format_data->address_info_item[j].length = 16;
   common_packet_format_data->address_info_item[j].sin_family = htons(AF_INET);
 
   return kEipStatusOk;