From 7bbc6991653232159d1e5c81c8328c688ab4afae Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Wed, 3 Feb 2021 14:07:23 +1100
Subject: [PATCH] Copter: make terrain failure strings human-readable

---
 ArduCopter/AP_Arming.cpp | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/ArduCopter/AP_Arming.cpp b/ArduCopter/AP_Arming.cpp
index de63d4b5cf..ab0a3b8b59 100644
--- a/ArduCopter/AP_Arming.cpp
+++ b/ArduCopter/AP_Arming.cpp
@@ -236,37 +236,38 @@ bool AP_Arming_Copter::parameter_checks(bool display_failure)
 #if MODE_RTL_ENABLED == ENABLED
         if (copter.mode_rtl.get_alt_type() == ModeRTL::RTLAltType::RTL_ALTTYPE_TERRAIN) {
             // get terrain source from wpnav
+            const char *failure_template = "RTL_ALT_TYPE is above-terrain but %s";
             switch (copter.wp_nav->get_terrain_source()) {
             case AC_WPNav::TerrainSource::TERRAIN_UNAVAILABLE:
-                check_failed(ARMING_CHECK_PARAMETERS, display_failure, "RTL_ALT_TYPE=1 but no terrain data");
+                check_failed(ARMING_CHECK_PARAMETERS, display_failure, failure_template, "no terrain data");
                 return false;
                 break;
             case AC_WPNav::TerrainSource::TERRAIN_FROM_RANGEFINDER:
                 if (!copter.rangefinder_state.enabled || !copter.rangefinder.has_orientation(ROTATION_PITCH_270)) {
-                    check_failed(ARMING_CHECK_PARAMETERS, display_failure, "RTL_ALT_TYPE=1 but no rangefinder");
+                    check_failed(ARMING_CHECK_PARAMETERS, display_failure, failure_template, "no rangefinder");
                     return false;
                 }
                 // check if RTL_ALT is higher than rangefinder's max range
                 if (copter.g.rtl_altitude > copter.rangefinder.max_distance_cm_orient(ROTATION_PITCH_270)) {
-                    check_failed(ARMING_CHECK_PARAMETERS, display_failure, "RTL_ALT_TYPE=1 but RTL_ALT>RNGFND_MAX_CM");
+                    check_failed(ARMING_CHECK_PARAMETERS, display_failure, failure_template, "RTL_ALT>RNGFND_MAX_CM");
                     return false;
                 }
                 break;
             case AC_WPNav::TerrainSource::TERRAIN_FROM_TERRAINDATABASE:
 #if AP_TERRAIN_AVAILABLE && AC_TERRAIN
                 if (!copter.terrain.enabled()) {
-                    check_failed(ARMING_CHECK_PARAMETERS, display_failure, "RTL_ALT_TYPE=1 but terrain disabled");
+                    check_failed(ARMING_CHECK_PARAMETERS, display_failure, failure_template, "terrain disabled");
                     return false;
                 }
                 // check terrain data is loaded
                 uint16_t terr_pending, terr_loaded;
                 copter.terrain.get_statistics(terr_pending, terr_loaded);
                 if (terr_pending != 0) {
-                    check_failed(ARMING_CHECK_PARAMETERS, display_failure, "RTL_ALT_TYPE=1, waiting for terrain data");
+                    check_failed(ARMING_CHECK_PARAMETERS, display_failure, failure_template, "waiting for terrain data");
                     return false;
                 }
 #else
-                check_failed(ARMING_CHECK_PARAMETERS, display_failure, "RTL_ALT_TYPE=1 but terrain disabled");
+                check_failed(ARMING_CHECK_PARAMETERS, display_failure, failure_template, "terrain disabled");
                 return false;
 #endif
                 break;