From 521f3dc4b9c380a0e160f81ba794fea57dd497cb Mon Sep 17 00:00:00 2001
From: Randy Mackay <rmackay9@yahoo.com>
Date: Tue, 21 Jul 2015 20:49:20 +0900
Subject: [PATCH] GCS_MAVLink: only forward msg once per channel

Issue found and alternative fix provided by Arthur Benemann
---
 libraries/GCS_MAVLink/MAVLink_routing.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libraries/GCS_MAVLink/MAVLink_routing.cpp b/libraries/GCS_MAVLink/MAVLink_routing.cpp
index 17bf45294a..56548b658b 100644
--- a/libraries/GCS_MAVLink/MAVLink_routing.cpp
+++ b/libraries/GCS_MAVLink/MAVLink_routing.cpp
@@ -127,11 +127,13 @@ bool MAVLink_routing::check_and_forward(mavlink_channel_t in_channel, const mavl
 
     // forward on any channels matching the targets
     bool forwarded = false;
+    bool sent_to_chan[MAVLINK_COMM_NUM_BUFFERS];
+    memset(sent_to_chan, 0, sizeof(sent_to_chan));
     for (uint8_t i=0; i<num_routes; i++) {
         if (broadcast_system || (target_system == routes[i].sysid &&
                                  (broadcast_component || 
                                   target_component == routes[i].compid))) {
-            if (in_channel != routes[i].channel) {
+            if (in_channel != routes[i].channel && !sent_to_chan[routes[i].channel]) {
                 if (comm_get_txspace(routes[i].channel) >= 
                     ((uint16_t)msg->len) + MAVLINK_NUM_NON_PAYLOAD_BYTES) {
 #if ROUTING_DEBUG
@@ -144,6 +146,7 @@ bool MAVLink_routing::check_and_forward(mavlink_channel_t in_channel, const mavl
 #endif
                     _mavlink_resend_uart(routes[i].channel, msg);
                 }
+                sent_to_chan[routes[i].channel] = true;
                 forwarded = true;
             }
         }