Carefule here - s_current_apk_folder could be nil which means the current folder is not within the apk package (Android doesn't unpack files from the app package onto the file system, so to emulate a 'real' filesystem, the engine redirects access to files relative to the engine folder into the app package). You need to do this:
```
if (s_current_apk_folder != nil)
  return MCStringGetCString(s_current_apk_folder);
return nil;
```