From 2cb93f5a167912ba720b0b9fe8ef4468ad627757 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Sun, 9 Oct 2011 22:00:26 +1100
Subject: [PATCH] fixed a crash in HIL

The g_rc_function[RC_Channel_aux::k_flap_auto] ptr came out as NULL
during one HIL run on a desktop CPU, which led to ArduPlane
crashing. I am not yet sure if this can happen in real flight, but I
think the NULL check is worthwhile to be sure.
---
 ArduPlane/Attitude.pde | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/ArduPlane/Attitude.pde b/ArduPlane/Attitude.pde
index 13af736483..a951873a4c 100644
--- a/ArduPlane/Attitude.pde
+++ b/ArduPlane/Attitude.pde
@@ -377,8 +377,9 @@ static void set_servos(void)
 		} else {
 			G_RC_AUX(k_flap_auto)->servo_out = g.flap_2_percent;
 		}
-		g_rc_function[RC_Channel_aux::k_flap_auto]->calc_pwm();
-
+        if (g_rc_function[RC_Channel_aux::k_flap_auto] != NULL) {
+            g_rc_function[RC_Channel_aux::k_flap_auto]->calc_pwm();
+        }
 	}
 	
 #if HIL_MODE == HIL_MODE_DISABLED || HIL_SERVOS