rem: if (mtx->thread_id != thread_id)
add: if (!mtx->locks || mtx->thread_id != thread_id)
context: UnlockRecursiveMutex_SDL (RecursiveMutex val){	RecM *mtx = (RecM *)val;	Uint32 thread_id = SDL_ThreadID();	if (mtx->thread_id != thread_id)	{#ifdef NAMED_SYNCHRO		fprintf (stderr, "'%s' attempted to unlock %s when it didn't hold it\n", MyThreadName (), mtx->name);#endif	}	else	{		mtx->locks--;		if (!mtx->locks)		{			mtx->thread_id = 0;			SDL_mutexV (mtx->mutex);		}	}}