QWidget::restoreGeometry does not properly work for a central widget in QMainWindow if QDockWidget is present

When having a dockwidget docked in a main window that has central widget present, saving and restoring geometry to the central widget does not properly work.

Steps to reproduce:

• Run attached sample
• Resize the dock widget few pixels
• Press "Hide" button that saves geometry of the central widget and hides it
• Press "Show" button that shows the central widget and restores geometry to it
• EXPECTED: central widget's geometry is identical to what it was before hiding it
• ACTUAL: central widget's geometry is minimal, with dockwidget hogging up all available space

The issue does not reproduce if the dockwidget is not resized. Also, calling save/restoreState works properly as a workaround.