From 1aa484aee5af0dcd89fcc5be9248f9d59363b3c0 Mon Sep 17 00:00:00 2001
From: Torsten Dreyer <Torsten@t3r.de>
Date: Fri, 6 Aug 2010 08:44:34 +0200
Subject: [PATCH] Fix segfault on invalid command line arguments

If FlightGear terminated before the FDM was instantiated it crashed.
---
 src/FDM/fdm_shell.cxx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/FDM/fdm_shell.cxx b/src/FDM/fdm_shell.cxx
index bec319c09..a4cfad309 100644
--- a/src/FDM/fdm_shell.cxx
+++ b/src/FDM/fdm_shell.cxx
@@ -98,7 +98,7 @@ void FDMShell::bind()
 
 void FDMShell::unbind()
 {
-  _impl->unbind();
+  if( _impl ) _impl->unbind();
 }
 
 void FDMShell::update(double dt)