title: ? symbols from LUA
body: <p>I've registered LUA api function by using:</p>
  
  <pre><code>lua_register( luaState, "someFunc", aaa::someFunc);
  </code></pre>
  
  <p>this function has to load a string from the someFunc's argument.</p>
  
  <p>I am doing it with:</p>
  
  <pre><code>int aaa::someFunc( lua_State* state ) {
      const char* _arg = ( const char* )lua_tostring( state, -1 );
  
      // ...
  
      return 0;
  }
  </code></pre>
  
  <p>it works ok, until I put to someFunc() some symbols of my language like: ą, ł, ź etc (it's 'a', 'l', 'z' written holding ALT key). For these symbols qDebug( "%s", _arg )* gives me only "?" for them all. How to recognize these values in my program?</p>
  
  <p>For example when I use in my script sendFunc( "Aaś" ) the printed _arg is "Aa?".</p>
  
  <p>*qDebug is from Qt library, it works the same as printf() but outputs to debug window.</p>
  
  <p>Thanks.</p>