Regression - DxDiag (and other DDraw applications) crash when executed in fullscreen mode

VBox 4.3.40 with VBEMP, ReactOS inbuilt Mesa
tested on ross gcc dbg builds:
0.4.10-dev-628-gab243b8 affected
0.4.10-dev-550-gc97e9de affected (after Thomas two D3D patches)
0.4.10-dev-548-g9bffdcb affected (before Thomas two D3D patches)

ReactOS 0.4.9official release was not affected yet, 0.4.8official release was not affected yet (both were still based on WineD3D 3.0)
A regression

Reproduction steps
Open dxdiag and let it complete the DirectDraw selftest, watch carefully when it wants to draw in fullscreen

Expected result
It should be able to draw in fullscreen and when it finishes it should properly restore the desktop resolution (of 800x600 in my case), no black bars should surround the desktop area

Observed result
DxDiag will crash when trying to paint in fullscreen.
(When it finishes, it will not properly restore desktop, the desktop area is limited to something like 640x480. The rest is filled with black colour.
The user can fix this state by changing the desktop resolution via desk.cpl manually afterwards.)

0.4.10-dev-628-gab243b8__canNotRestoreDesktopResolution.webm
0.4.10-dev-628-gab243b8__canNotRestoreDesktopResolution.log

Sidenote: applications like Diablo II are affected from this as well and crash in fullscreen now.