QFactoryLoader is not thread-safe

Single sql connection should not be used from a different thread that it is created in (and some drivers may have additional limitations). Correct me if I am wrong, but I believe it should be working in a way that I implemented it in attached example.

This does not happen every time, but running this example 10 times usually fails somewhere.

Sometimes error messages are printed, such as:

QObject::moveToThread: Current thread (0x2577340) is not the object's thread (0x2577960).
Cannot move to target thread (0x25701e0)

QObject::moveToThread: Current thread (0x25759a0) is not the object's thread (0x2577960).
Cannot move to target thread (0x25701e0)

QObject::moveToThread: Current thread (0x25766e0) is not the object's thread (0x2577960).
Cannot move to target thread (0x25701e0)

Sometimes there is an assert:

ASSERT: "!weakref.load()" in file ../../../../include/QtCore/../../src/corelib/tools/qsharedpointer_impl.h, line 149

It may also get stuck in qt_call_post_routines() (qcoreapplication.cpp) calling (list->takeFirst())() which makes calls to cleanDriverDict continuously.

Sometimes it may even crash (see attachment). Sometimes it crashes inside sqlite library too.