[CsMain] Not sure, but maybe there's a bug

[<gr...@gm...>]

Hello,

in the thing plugin i found a little bug. To reproduce the error you can try
to run "awstest", and see if you get an NULL pointer exception.

 If I load the engine using:

 engine = CS_LOAD_PLUGIN(plugin_mgr, "crystalspace.engine.3d", iEngine);

and then register it in the object registry afterwards with:

object_reg->Register (engine, "iEngine");

I will surely get what I do not want, because when I load the engine plugin
(in the above LOAD_PLUGIN(...)), the C++ code of the "thing" plugin mesh
assumes that the engine was already registered inside the object registry:
in fact in the initialization of the "engine" plugin:

bool csEngine::Initialize (iObjectRegistry *object_reg)
{
.....
if (!thing_type)
  {
    thing_type = CS_LOAD_PLUGIN
(plugin_mgr,"crystalspace.mesh.object.thing", iMeshObjectType);
....

as usually, CS_LOAD_PLUGIN will then call:

bool csThingObjectType::Initialize (iObjectRegistry *object_reg)
{
  csThingObjectType::object_reg = object_reg;
  csRef<iEngine> e = CS_QUERY_REGISTRY (object_reg,
iEngine);<<<<<<<<<<<<<<<<<!!!!!!!!!
  engine = e; // We don't want a real ref here to avoid circular refs.

which will set the "engine" member variable of the class csThingObjectType
to NULL, if the engine plugin was not already registered.

A simple patch could be that the engine register itself into the register,
such as:

bool csEngine::Initialize (iObjectRegistry *object_reg)
{
  csEngine::object_reg = object_reg;

  object_reg->Register (this,"iEngine");//ADD THIS LINE!!!!!

  virtual_clock = CS_QUERY_REGISTRY (object_reg, iVirtualClock);
  if (!virtual_clock) return false;
...........


Greetings!


p.s. I noticed that the method   "bool csObjectRegistry::Register (iBase*,
char const* tag) ;" returns "false" if  "tag" was already used. So for
example if i register the same csEngine object 2 time i.e.:

objReg->Register(engine,"iEngine");//this will returns true
objReg->Register(engine,"iEngine");//this will returns false

and the second call will return "false", but it should return "true" IMO,
that is:

bool csObjectRegistry::Register (iBase* obj, char const* tag)
{
...........
      if (o)
      {
        // DecRef() o because Get() already increffed it.
        if(o == obj)//LINE ADDED
        {//LINE ADDED
            o->DecRef ();
            return true; //LINE ADDED
         }//LINE ADDED
       o->DecRef ();
        return false;
      }