QSplitter on Cocoa loses cursor when other window gets focus.

QSplitter loses its cursor when an QWidget popup

Groups and a line edit are required to reproduce this issue, setting line edit to readonly (not accept focus) is enough to stop the issue from occurring.

Run the attached example and mouse over the splitter, notice the cursor changes.
press the button.
Press the button on the new widget to return to the original
mouse over again and notice the cursor does not change.

To get it back two ways:
1. move the splitter
2 resize its parent windows

The sample includes an event filter that can be used as a workaround for the problem.