Run the small attached sample. Click on the 1st window to activate it -> crash (see picture of crash point in qnsview.mm)
The debugger says:
"[NSCursor set]: message sent to deallocated instance"
(I have Zombie enabled under XCode 5)
This is a Cocoa issue of Qt 5.x.
After some more analysis of the problem, I found the following:
QCocoaWindow stores a copy of a NSCursor in QCocoaWindow::m_windowCursor (cf. QCocoaWindow::setWindowCursor)
but this becomes a dangling pointer later when:
QCocoaCursor::changeCursor is called, which itself calls convertCursor and the line [cocoaCursor release] is reached
My guess is that this is the root of the problem.