From 1222e9b09476da09d3a3666a7c0d542b523b579d Mon Sep 17 00:00:00 2001
From: jmt <jmt>
Date: Mon, 26 Apr 2010 16:04:41 +0000
Subject: [PATCH] Fix a crash if startup fails before the navradio is inited.

---
 src/Instrumentation/navradio.cxx | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/Instrumentation/navradio.cxx b/src/Instrumentation/navradio.cxx
index b3d621b7d..cdf617530 100644
--- a/src/Instrumentation/navradio.cxx
+++ b/src/Instrumentation/navradio.cxx
@@ -129,9 +129,14 @@ FGNavRadio::FGNavRadio(SGPropertyNode *node) :
 // Destructor
 FGNavRadio::~FGNavRadio() 
 {
-    gps_course_node->removeChangeListener(this);
-    nav_slaved_to_gps_node->removeChangeListener(this);
-  
+    if (gps_course_node) {
+      gps_course_node->removeChangeListener(this);
+    }
+    
+    if (nav_slaved_to_gps_node) {
+      nav_slaved_to_gps_node->removeChangeListener(this);
+    }
+    
     delete term_tbl;
     delete low_tbl;
     delete high_tbl;
-- 
2.39.5