BGE fix: game object to controller links consistancy maintained regardless of order of deletion

AddObject actuator forces last created object to hang in memory even after object is removed from scene => bad link between object and physic controller that causes Blender to crash in case a python script tries to use it (bad programming anyway). 
This patch avoids the crash by maintaining consistent links at all time.

4 files changed, 46 insertions, 11 deletions

diff --git a/source/gameengine/Ketsji/KX_BulletPhysicsController.cpp b/source/gameengine/Ketsji/KX_BulletPhysicsController.cpp
index aa5d1f1cec1..aa7c75e9633 100644
--- a/source/gameengine/Ketsji/KX_BulletPhysicsController.cpp
+++ b/source/gameengine/Ketsji/KX_BulletPhysicsController.cpp
@@ -24,7 +24,18 @@ CcdPhysicsController(ci)
 	
 KX_BulletPhysicsController::~KX_BulletPhysicsController ()
 {
-
+	// The game object has a direct link to 
+	if (m_pObject)
+	{
+		// If we cheat in SetObject, we must also cheat here otherwise the 
+		// object will still things it has a physical controller
+		// Note that it requires that m_pObject is reset in case the object is deleted
+		// before the controller (usual case, see KX_Scene::RemoveNodeDestructObjec)
+		// The non usual case is when the object is not deleted because its reference is hanging
+		// in a AddObject actuator but the node is deleted. This case is covered here.
+		KX_GameObject* gameobj = (KX_GameObject*)	m_pObject->GetSGClientObject();
+		gameobj->SetPhysicsController(NULL,false);
+	}
 }
 
 void	KX_BulletPhysicsController::resolveCombinedVelocities(float linvelX,float linvelY,float linvelZ,float angVelX,float angVelY,float angVelZ)
@@ -58,6 +69,7 @@ void	KX_BulletPhysicsController::SetObject (SG_IObject* object)
 
 }
 
+
 void	KX_BulletPhysicsController::setMargin (float collisionMargin)
 {
 	CcdPhysicsController::SetMargin(collisionMargin);
diff --git a/source/gameengine/Ketsji/KX_GameObject.cpp b/source/gameengine/Ketsji/KX_GameObject.cpp
index 67c82ee2082..bc608d26c50 100644
--- a/source/gameengine/Ketsji/KX_GameObject.cpp
+++ b/source/gameengine/Ketsji/KX_GameObject.cpp
@@ -105,7 +105,19 @@ KX_GameObject::~KX_GameObject()
 	delete m_pClient_info;
 	//if (m_pSGNode)
 	//	delete m_pSGNode;
-	
+	if (m_pSGNode)
+	{
+		// must go through controllers and make sure they will not use us anymore
+		// This is important for KX_BulletPhysicsControllers that unregister themselves
+		// from the object when they are deleted.
+		SGControllerList::iterator contit;
+		SGControllerList& controllers = m_pSGNode->GetSGControllerList();
+		for (contit = controllers.begin();contit!=controllers.end();++contit)
+		{
+			(*contit)->ClearObject();
+		}
+		m_pSGNode->SetSGClientObject(NULL);
+	}
 }
 
 
diff --git a/source/gameengine/Ketsji/KX_Scene.cpp b/source/gameengine/Ketsji/KX_Scene.cpp
index 633b57ef209..526f893df5a 100644
--- a/source/gameengine/Ketsji/KX_Scene.cpp
+++ b/source/gameengine/Ketsji/KX_Scene.cpp
@@ -410,8 +410,15 @@ void KX_Scene::EnableZBufferClearing(bool isclearingZbuffer)
 void KX_Scene::RemoveNodeDestructObject(class SG_IObject* node,class CValue* gameobj)
 {
 	KX_GameObject* orgobj = (KX_GameObject*)gameobj;	
-	NewRemoveObject(orgobj);
-
+	if (NewRemoveObject(orgobj) != 0)
+	{
+		// object is not yet deleted (this can happen when it hangs in an add object actuator
+		// last object created reference. It's a bad situation, don't know how to fix it exactly
+		// The least I can do, is remove the reference to the node in the object as the node
+		// will in any case be deleted. This ensures that the object will not try to use the node
+		// when it is finally deleted (see KX_GameObject destructor)
+		orgobj->SetSGNode(NULL);
+	}
 	if (node)
 		delete node;
 }
@@ -723,8 +730,9 @@ void KX_Scene::DelayedRemoveObject(class CValue* gameobj)
 
 
 
-void KX_Scene::NewRemoveObject(class CValue* gameobj)
+int KX_Scene::NewRemoveObject(class CValue* gameobj)
 {
+	int ret;
 	KX_GameObject* newobj = (KX_GameObject*) gameobj;
 
 	//todo: look at this
@@ -768,16 +776,17 @@ void KX_Scene::NewRemoveObject(class CValue* gameobj)
 	}
 	
 	newobj->RemoveMeshes();
+	ret = 1;
 	if (m_objectlist->RemoveValue(newobj))
-		newobj->Release();
+		ret = newobj->Release();
 	if (m_tempObjectList->RemoveValue(newobj))
-		newobj->Release();
+		ret = newobj->Release();
 	if (m_parentlist->RemoveValue(newobj))
-		newobj->Release();
+		ret = newobj->Release();
 	if (m_inactivelist->RemoveValue(newobj))
-		newobj->Release();
+		ret = newobj->Release();
 	if (m_euthanasyobjects->RemoveValue(newobj))
-		newobj->Release();
+		ret = newobj->Release();
 		
 	if (newobj == m_active_camera)
 	{
@@ -787,6 +796,8 @@ void KX_Scene::NewRemoveObject(class CValue* gameobj)
 	}
 	if (m_sceneConverter)
 		m_sceneConverter->UnregisterGameObject(newobj);
+	// return value will be 0 if the object is actually deleted (all reference gone)
+	return ret;
 }
 
 
diff --git a/source/gameengine/Ketsji/KX_Scene.h b/source/gameengine/Ketsji/KX_Scene.h
index 4c3b1d2e558..58120d49dc4 100644
--- a/source/gameengine/Ketsji/KX_Scene.h
+++ b/source/gameengine/Ketsji/KX_Scene.h
@@ -306,7 +306,7 @@ public:
 	
 	void DelayedReleaseObject(CValue* gameobj);
 
-	void NewRemoveObject(CValue* gameobj);
+	int NewRemoveObject(CValue* gameobj);
 	void ReplaceMesh(CValue* gameobj,
 					 void* meshobj);
 	void AddShape(class btCollisionShape* shape);