4.7/Cocoa: Focus handling problem in sheets on Mac OS prevent keyboard shortcuts from working

There is some issue that prevents keyboard shortcuts from working in a dialog presented as a sheet on Mac OS with Qt 4.7/Cocoa.

The problem has something to do with the keyboard focus and is a change in behavior from 4.6.

I've attached a small test application.

Run the test application and click the 'Push Me' button. A sheet will appear. Now try to type Cmd-D or Escape to shortcut the buttons in the dialog. Under 4.7 it fails. Under 4.6 it works.

Now click in the text in the sheet. Once a cursor appears (indicating that the sheet has somehow received focus), the Cmd-D or Escape keys work to close the dialog.