Problems with threads and windows

[jacek]

Yes this could cause an error but I made it this way because if you see the example /examples/threads/mandelbrot passes a reference to the generated image too.

I've checked that example and Qt sources and it looks like emit makes a copy of those parameters, even when you pass then as a reference.

I hope you have noticed this:

With queued connections, Qt must store a copy of the arguments that were passed to the signal so that it can pass them to the slot later on. Qt knows how to take of copy of many C++ and Qt types, but QImage isn't one of them. We must therefore call the template function qRegisterMetaType() before we can use QImage as parameter in queued connections.