From be603da5793a70414ecf33e95ef42b3b55d6de5d Mon Sep 17 00:00:00 2001
From: Randy Mackay <rmackay9@yahoo.com>
Date: Thu, 27 Aug 2015 20:54:09 +0900
Subject: [PATCH] Copter: fix optflow position_ok check

We should accept predicted relative horizontal position only when disarmed
---
 ArduCopter/system.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/ArduCopter/system.cpp b/ArduCopter/system.cpp
index a325ad98de..e1fd038efa 100644
--- a/ArduCopter/system.cpp
+++ b/ArduCopter/system.cpp
@@ -353,7 +353,13 @@ bool Copter::optflow_position_ok()
 
     // get filter status from EKF
     nav_filter_status filt_status = inertial_nav.get_filter_status();
-    return (filt_status.flags.horiz_pos_rel || filt_status.flags.pred_horiz_pos_rel);
+
+    // if disarmed we accept a predicted horizontal relative position
+    if (!motors.armed()) {
+        return (filt_status.flags.pred_horiz_pos_rel);
+    } else {
+        return (filt_status.flags.horiz_pos_rel && !filt_status.flags.const_pos_mode);
+    }
 #endif
 }