From 67d8965cade467a0cf06a4c974359e72217418ae Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Wed, 3 Aug 2022 22:59:38 +1000
Subject: [PATCH] ArduCopter: make terrain checks common between Copter and
 Plane

---
 ArduCopter/AP_Arming.cpp | 28 ++++++++++++----------------
 ArduCopter/AP_Arming.h   |  4 ++++
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/ArduCopter/AP_Arming.cpp b/ArduCopter/AP_Arming.cpp
index 18cdceeca0..2f1f3a0756 100644
--- a/ArduCopter/AP_Arming.cpp
+++ b/ArduCopter/AP_Arming.cpp
@@ -120,6 +120,17 @@ bool AP_Arming_Copter::board_voltage_checks(bool display_failure)
     return true;
 }
 
+// expected to return true if the terrain database is required to have
+// all data loaded
+bool AP_Arming_Copter::terrain_database_required() const
+{
+    if (copter.wp_nav->get_terrain_source() == AC_WPNav::TerrainSource::TERRAIN_FROM_TERRAINDATABASE &&
+        copter.mode_rtl.get_alt_type() == ModeRTL::RTLAltType::RTL_ALTTYPE_TERRAIN) {
+        return true;
+    }
+    return AP_Arming::terrain_database_required();
+}
+
 bool AP_Arming_Copter::parameter_checks(bool display_failure)
 {
     // check various parameter values
@@ -228,22 +239,7 @@ bool AP_Arming_Copter::parameter_checks(bool display_failure)
                 }
                 break;
             case AC_WPNav::TerrainSource::TERRAIN_FROM_TERRAINDATABASE:
-#if AP_TERRAIN_AVAILABLE
-                if (!copter.terrain.enabled()) {
-                    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, failure_template, "waiting for terrain data");
-                    return false;
-                }
-#else
-                check_failed(ARMING_CHECK_PARAMETERS, display_failure, failure_template, "terrain disabled");
-                return false;
-#endif
+                // these checks are done in AP_Arming
                 break;
             }
         }
diff --git a/ArduCopter/AP_Arming.h b/ArduCopter/AP_Arming.h
index e1a32ed20a..58f8e78670 100644
--- a/ArduCopter/AP_Arming.h
+++ b/ArduCopter/AP_Arming.h
@@ -51,6 +51,10 @@ protected:
 
     void set_pre_arm_check(bool b);
 
+    // expected to return true if the terrain database is required to have
+    // all data loaded
+    bool terrain_database_required() const override;
+
 private:
 
     // actually contains the pre-arm checks.  This is wrapped so that