From 09905bb2f21ff33806341c95fd0c0e56a2040150 Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Wed, 5 Dec 2018 12:04:00 +1100
Subject: [PATCH] GCS_MAVLink: send data for sensors even if no data for other
 sensors

This is notable when you have a lot of compasses, for example
---
 libraries/GCS_MAVLink/GCS_Common.cpp | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/libraries/GCS_MAVLink/GCS_Common.cpp b/libraries/GCS_MAVLink/GCS_Common.cpp
index b8440abf84..9942fae2d7 100644
--- a/libraries/GCS_MAVLink/GCS_Common.cpp
+++ b/libraries/GCS_MAVLink/GCS_Common.cpp
@@ -1659,16 +1659,24 @@ void GCS_MAVLINK::send_scaled_imu(uint8_t instance, void (*send_fn)(mavlink_chan
     const AP_InertialSensor &ins = AP::ins();
     const Compass &compass = AP::compass();
 
-    if (ins.get_gyro_count() <= instance ||
-        ins.get_accel_count() <= instance) {
-        return;
+    bool have_data = false;
+    Vector3f accel{};
+    if (ins.get_accel_count() > instance) {
+        accel = ins.get_accel(instance);
+        have_data = true;
+    }
+    Vector3f gyro{};
+    if (ins.get_accel_count() > instance) {
+        gyro = ins.get_gyro(instance);
+        have_data = true;
     }
-
-    const Vector3f &accel = ins.get_accel(instance);
-    const Vector3f &gyro = ins.get_gyro(instance);
     Vector3f mag{};
     if (compass.get_count() > instance) {
         mag = compass.get_field(instance);
+        have_data = true;
+    }
+    if (!have_data) {
+        return;
     }
     send_fn(
         chan,