[Development] Qt 5 QMessageBox doesn't respond?

[Stephen Chu]

I am wondering if this is the result of switching qtbase to master 
instead of staying wiht qt5.

When I call this on a Mac:

	QMessageBox::warning(NULL, "", "warning!");

The dialog shows up but clicking at the OK button doesn't dismiss it. 
And QMessageBox code is taking 100% of a core spinning.

Before I file a bug report, can someone with latest qtbase (from 
yesterday) try this?

Thanks.