From bbccdce22926cbecf86310b5ec74c02bc5798a01 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Thu, 22 Dec 2016 15:46:26 +1100
Subject: [PATCH] AP_Terrain: prevent use of invalid Location

loc is not initialised and can cause a fault on startup
---
 libraries/AP_Terrain/AP_Terrain.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/AP_Terrain/AP_Terrain.cpp b/libraries/AP_Terrain/AP_Terrain.cpp
index def509e77b..aabfc88994 100644
--- a/libraries/AP_Terrain/AP_Terrain.cpp
+++ b/libraries/AP_Terrain/AP_Terrain.cpp
@@ -316,7 +316,7 @@ void AP_Terrain::update(void)
     // update the cached current location height
     Location loc;
     bool pos_valid = ahrs.get_position(loc);
-    bool terrain_valid = height_amsl(loc, height, false);
+    bool terrain_valid = pos_valid && height_amsl(loc, height, false);
     if (pos_valid && terrain_valid) {
         last_current_loc_height = height;
         have_current_loc_height = true;