[Libqtlua-list] Lingering QtLua::Functions after QtLua::State cleans the environment

[David Palacio]

Hi,

I bind some C++ QtLua::Functions and some of them are referenced inside Lua
modules. These functions may throw an exception (Lua userdata is no
QtLua::UserData) if they are deleted when the State is being deleted. I
tracked the problem to a non existant metatable State::_key_item_metatable in
the registry. This check in qtluauserdata.cc:51 fails:
    inline QtLua::Ref<UserData> UserData::get_ud_(lua_State *st, int i)
    {
    #ifndef QTLUA_NO_USERDATA_CHECK
      if (lua_getmetatable(st, i))
        {
          lua_pushlightuserdata(st, &State::_key_item_metatable);
          lua_rawget(st, LUA_REGISTRYINDEX);

          if (lua_rawequal(st, -2, -1))

The State::_key_item_metatable metatable is already deleted so this check
fails.

So, who deletes the metatable? QtLua::State does. May I know what for? Since
Lua should be able to take care of cleaning the environment and calling gc
methods when lua_close is called. I attach a patch that leaves the cleaning
responsability to lua_close.

Regards,

David.

0001-Let-the-Lua-VM-take-care-of-cleaning-the-environment.patch
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