From 287cc74965e11ff3888117a9d9b88ed2bdbb9252 Mon Sep 17 00:00:00 2001
From: Erik Hofman <erik@ehofman.com>
Date: Sun, 30 Jan 2011 11:04:37 +0100
Subject: [PATCH] Fix for bug #204 and #222 by Bertrand Coconnier; NaNs (bug
 #222) were basically generated because the method JSBSim::unbind() was not
 implemented in JSBSim.cxx.

---
 src/FDM/JSBSim/JSBSim.cxx              | 47 +++++++++++++++-----------
 src/FDM/JSBSim/JSBSim.hxx              |  5 +--
 src/FDM/JSBSim/models/FGPropulsion.cpp |  8 +++--
 3 files changed, 36 insertions(+), 24 deletions(-)

diff --git a/src/FDM/JSBSim/JSBSim.cxx b/src/FDM/JSBSim/JSBSim.cxx
index f802c8c2e..a9e9be771 100644
--- a/src/FDM/JSBSim/JSBSim.cxx
+++ b/src/FDM/JSBSim/JSBSim.cxx
@@ -144,8 +144,6 @@ FGJSBsim::FGJSBsim( double dt )
         }
     }
 
-    resetPropertyState();
-    
     fdmex = new FGFDMExec( (FGPropertyManager*)globals->get_props() );
 
     // Register ground callback.
@@ -424,6 +422,33 @@ void FGJSBsim::init()
 
 /******************************************************************************/
 
+void checkTied ( FGPropertyManager *node )
+{
+  int N = node->nChildren();
+  string name;
+
+  for (int i=0; i<N; i++) {
+    if (node->getChild(i)->nChildren() ) {
+      checkTied( (FGPropertyManager*)node->getChild(i) );
+    }
+    if ( node->getChild(i)->isTied() ) {
+      name = ((FGPropertyManager*)node->getChild(i))->GetFullyQualifiedName();
+      node->Untie(name);
+    }
+  }
+}
+
+/******************************************************************************/
+
+void FGJSBsim::unbind()
+{
+  SGPropertyNode* instance = globals->get_props()->getNode("/fdm/jsbsim");
+  checkTied((FGPropertyManager*)instance);
+  FGInterface::unbind();
+}
+
+/******************************************************************************/
+
 // Run an iteration of the EOM (equations of motion)
 
 void FGJSBsim::update( double dt )
@@ -1415,21 +1440,3 @@ void FGJSBsim::update_external_forces(double t_off)
     fgSetDouble("/fdm/jsbsim/systems/hook/tailhook-pos-deg", fi);
 }
 
-void FGJSBsim::resetPropertyState()
-{
-// this code works-around bug #222:
-// http://code.google.com/p/flightgear-bugs/issues/detail?id=222
-// for whatever reason, having an existing value for the WOW
-// property causes the NaNs. Should that be fixed, this code can die
-  SGPropertyNode* gear = fgGetNode("/fdm/jsbsim/gear", false);
-  if (!gear) {
-    return;
-  }
-  
-  int index = 0;
-  SGPropertyNode* unitNode = NULL;
-  for (; (unitNode = gear->getChild("unit", index)) != NULL; ++index) {
-    unitNode->removeChild("WOW", 0, false);
-  }
-}
-
diff --git a/src/FDM/JSBSim/JSBSim.hxx b/src/FDM/JSBSim/JSBSim.hxx
index 1a8037167..a01146bcc 100644
--- a/src/FDM/JSBSim/JSBSim.hxx
+++ b/src/FDM/JSBSim/JSBSim.hxx
@@ -110,6 +110,9 @@ public:
     /// Reset flight params to a specific position
     void init();
 
+    /// Unbind properties
+    void unbind();
+
     /// @name Position Parameter Set
     //@{
     /** Set geocentric latitude
@@ -283,8 +286,6 @@ private:
     void update_gear(void);
 
     void update_external_forces(double t_off);
-
-    void resetPropertyState();
 };
 
 
diff --git a/src/FDM/JSBSim/models/FGPropulsion.cpp b/src/FDM/JSBSim/models/FGPropulsion.cpp
index 57d2852f3..05a2da4c4 100644
--- a/src/FDM/JSBSim/models/FGPropulsion.cpp
+++ b/src/FDM/JSBSim/models/FGPropulsion.cpp
@@ -307,18 +307,23 @@ bool FGPropulsion::Load(Element* el)
     try {
       if (type == "piston_engine") {
         HavePistonEngine = true;
+        if (!IsBound) bind();
         Engines.push_back(new FGPiston(FDMExec, document, numEngines));
       } else if (type == "turbine_engine") {
         HaveTurbineEngine = true;
+        if (!IsBound) bind();
         Engines.push_back(new FGTurbine(FDMExec, document, numEngines));
       } else if (type == "turboprop_engine") {
         HaveTurboPropEngine = true;
+        if (!IsBound) bind();
         Engines.push_back(new FGTurboProp(FDMExec, document, numEngines));
       } else if (type == "rocket_engine") {
         HaveRocketEngine = true;
+        if (!IsBound) bind();
         Engines.push_back(new FGRocket(FDMExec, document, numEngines));
       } else if (type == "electric_engine") {
         HaveElectricEngine = true;
+        if (!IsBound) bind();
         Engines.push_back(new FGElectric(FDMExec, document, numEngines));
       } else {
         cerr << "Unknown engine type: " << type << endl;
@@ -345,7 +350,6 @@ bool FGPropulsion::Load(Element* el)
   if (el->FindElement("dump-rate"))
     DumpRate = el->FindElementValueAsNumberConvertTo("dump-rate", "LBS/MIN");
 
-  if (!IsBound) bind();
   PostLoad(el, PropertyManager);
 
   return true;
@@ -642,7 +646,7 @@ void FGPropulsion::bind(void)
   typedef int (FGPropulsion::*iPMF)(void) const;
 
   IsBound = true;
-  PropertyManager->Tie("propulsion/set-running", this, (iPMF)0, &FGPropulsion::InitRunning, true);
+  PropertyManager->Tie("propulsion/set-running", this, (iPMF)0, &FGPropulsion::InitRunning, false);
   if (HaveTurbineEngine) {
     PropertyManager->Tie("propulsion/starter_cmd", this, (iPMF)0, &FGPropulsion::SetStarter,  true);
     PropertyManager->Tie("propulsion/cutoff_cmd", this,  (iPMF)0, &FGPropulsion::SetCutoff,   true);
-- 
2.39.2