From e8237c8930c59f83ed7b379e023c713b53015938 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Tue, 15 Oct 2024 19:24:26 +1100
Subject: [PATCH] Plane: more places checking for terrain alt

---
 ArduPlane/ArduPlane.cpp   | 2 +-
 ArduPlane/GCS_Mavlink.cpp | 2 +-
 ArduPlane/mode_guided.cpp | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/ArduPlane/ArduPlane.cpp b/ArduPlane/ArduPlane.cpp
index 0181f392d804b9..5f1a6e5717b840 100644
--- a/ArduPlane/ArduPlane.cpp
+++ b/ArduPlane/ArduPlane.cpp
@@ -859,7 +859,7 @@ bool Plane::set_target_location(const Location &target_loc)
         return false;
     }
     // add home alt if needed
-    if (loc.relative_alt) {
+    if (loc.relative_alt && !loc.terrain_alt) {
         loc.alt += plane.home.alt;
         loc.relative_alt = 0;
     }
diff --git a/ArduPlane/GCS_Mavlink.cpp b/ArduPlane/GCS_Mavlink.cpp
index 45f8c3338eedfc..591f40d68b8100 100644
--- a/ArduPlane/GCS_Mavlink.cpp
+++ b/ArduPlane/GCS_Mavlink.cpp
@@ -749,7 +749,7 @@ bool GCS_MAVLINK_Plane::handle_guided_request(AP_Mission::Mission_Command &cmd)
 void GCS_MAVLINK_Plane::handle_change_alt_request(AP_Mission::Mission_Command &cmd)
 {
     plane.next_WP_loc.alt = cmd.content.location.alt;
-    if (cmd.content.location.relative_alt) {
+    if (cmd.content.location.relative_alt && !cmd.content.location.terrain_alt) {
         plane.next_WP_loc.alt += plane.home.alt;
     }
     plane.next_WP_loc.relative_alt = false;
diff --git a/ArduPlane/mode_guided.cpp b/ArduPlane/mode_guided.cpp
index a97bedcd7dffbb..cb4a1ccd4baa46 100644
--- a/ArduPlane/mode_guided.cpp
+++ b/ArduPlane/mode_guided.cpp
@@ -109,7 +109,7 @@ void ModeGuided::navigate()
 bool ModeGuided::handle_guided_request(Location target_loc)
 {
     // add home alt if needed
-    if (target_loc.relative_alt) {
+    if (target_loc.relative_alt && !target_loc.terrain_alt) {
         target_loc.alt += plane.home.alt;
         target_loc.relative_alt = 0;
     }