Fix crash when adding a NULL object to the cache

components/resource/bulletshapemanager.cpp

@@ -141,11 +141,8 @@ osg::ref_ptr<const BulletShape> BulletShapeManager::getShape(const std::string &
             node->accept(visitor);
             shape = visitor.getShape();
             if (!shape)
-            {
-                mCache->addEntryToObjectCache(normalized, NULL);
                 return osg::ref_ptr<BulletShape>();
         }
-        }
 
         mCache->addEntryToObjectCache(normalized, shape);
     }
@@ -158,6 +155,7 @@ osg::ref_ptr<BulletShapeInstance> BulletShapeManager::cacheInstance(const std::s
     mVFS->normalizeFilename(normalized);
 
     osg::ref_ptr<BulletShapeInstance> instance = createInstance(normalized);
+    if (instance)
         mInstanceCache->addEntryToObjectCache(normalized, instance.get());
     return instance;
 }

components/resource/multiobjectcache.cpp

@@ -51,6 +51,11 @@ namespace Resource
 
     void MultiObjectCache::addEntryToObjectCache(const std::string &filename, osg::Object *object)
     {
+        if (!object)
+        {
+            OSG_ALWAYS << " trying to add NULL object to cache for " << filename << std::endl;
+            return;
+        }
         OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_objectCacheMutex);
         _objectCache.insert(std::make_pair(filename, object));
     }

components/resource/objectcache.cpp

@@ -34,6 +34,11 @@ ObjectCache::~ObjectCache()
 
 void ObjectCache::addEntryToObjectCache(const std::string& filename, osg::Object* object, double timestamp)
 {
+    if (!object)
+    {
+        OSG_ALWAYS << " trying to add NULL object to cache for " << filename << std::endl;
+        return;
+    }
     OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_objectCacheMutex);
     _objectCache[filename]=ObjectTimeStampPair(object,timestamp);
 }