From 61788d655863cd20f3ac5fd2fcaa59860f23bd14 Mon Sep 17 00:00:00 2001
From: Erik Hofman <erik@ehofman.com>
Date: Fri, 29 Oct 2010 09:10:07 +0200
Subject: [PATCH] temporary fix for a crash of the c172 (and possibly other
 aircraft)

---
 src/FDM/JSBSim/FGFDMExec.cpp | 6 ++++--
 src/FDM/JSBSim/FGFDMExec.h   | 1 +
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/FDM/JSBSim/FGFDMExec.cpp b/src/FDM/JSBSim/FGFDMExec.cpp
index bc81cd6f8..6a12cec2b 100644
--- a/src/FDM/JSBSim/FGFDMExec.cpp
+++ b/src/FDM/JSBSim/FGFDMExec.cpp
@@ -101,11 +101,13 @@ FGFDMExec::FGFDMExec(FGPropertyManager* root) : Root(root)
   FDMctr = new unsigned int;
   *FDMctr = 0;
   Initialize();
+  root_overload = (root != NULL);
 }
 
 FGFDMExec::FGFDMExec(FGPropertyManager* root, unsigned int* fdmctr) : Root(root), FDMctr(fdmctr)
 {
   Initialize();
+  root_overload = (root != NULL);
 }
 
 void FGFDMExec::Initialize()
@@ -194,12 +196,12 @@ FGFDMExec::~FGFDMExec()
     checkTied( instance );
     DeAllocate();
     
-    if (IdFDM == 0) { // Meaning this is no child FDM
+   if(FDMctr != 0 && !root_overload) {
       if(Root != 0) {
          delete Root;
          Root = 0;
       }
-      if(FDMctr != 0) {
+      if (IdFDM == 0) { // Meaning this is no child FDM
          delete FDMctr;
          FDMctr = 0;
       }
diff --git a/src/FDM/JSBSim/FGFDMExec.h b/src/FDM/JSBSim/FGFDMExec.h
index 231cadcaa..9d53cd1b5 100644
--- a/src/FDM/JSBSim/FGFDMExec.h
+++ b/src/FDM/JSBSim/FGFDMExec.h
@@ -524,6 +524,7 @@ private:
   bool Constructing;
   bool modelLoaded;
   bool IsChild;
+  bool root_overload;
   string modelName;
   string AircraftPath;
   string FullAircraftPath;
-- 
2.39.5