Maybe a bug of no corresponding ofRemoveListener for ofURLFileLoaderImpl::start()

Hi,

I noticed an runtime exception that raised in ofURLFileLoaderImpl::update(), after I finished a correct downloading process and deleted the ofURLFileLoader instance in my object.

It seems that the framework was trying to callback the handler(ofURLFileLoaderImpl::update) which has already gone.

So I checked the source code of ofURLFileLoader.cpp, and noticed there is:
void ofURLFileLoaderImpl::start() {
if (!isThreadRunning()) {
ofAddListener(ofEvents().update, this, &ofURLFileLoaderImpl::update);
startThread();
}
}

But there isn't corresponding ofRemoveListener() anywhere.

And it seems a bug? So I've tried using ofURLFileLoader as singleton, and no error occurs, and it can also explains the above source code, the callback does always exist.

Sorry for no call stack info and I have no proper environment for testing the above guess, but if the info helps, it might be fixed after the thread ends?

Thanks a lot!

Start in ofURLFileLoader.cpp by tracing ofURLFileLoaderImpl::start(), its update callback, and the object shutdown path. Verify whether the update listener can outlive a deleted ofURLFileLoaderImpl; done means a completed download can be destroyed without a callback into the removed object, with a reproducible test or call sequence confirming the fix.