QMdiArea tileSubWindows reorder on resize

When QMdiSubWindows are tiled using QMdiArea::tileSubWindows() the order of the tiles may change when the area is resized.

I looks like what happens is that the sub windows are re-tiled whenever the area is resized. The re-tiling will position the active sub window as the top-left tile.

Steps to reproduce:

• run app
• active (click on) right sub window
• resize main window
• observe that the sub windows has switched place