ZDoom

Mosr recent build where this is visible Dec 18 64 bit

As noticed when getting screenshots for the font scaling bug, when running GZDoom in a window in a widescreen ratio, the edges of the interpic and other full screen graphics have a border at the sides showing what ever was on the screen last.

Fortunately, to test the font scaling, I'd gone to a windowed mode to get some screenshots of views when the screenshot button doesn't work, and this flagged up the problem in this report.

To be clear, it happens in Windowed mode but does not seem to happen in full screen mode.

Problem slightly visible at the edges of the interpic:

Most obviously, the red numbers from the full screen HUD are visible in the bottom-right

After calling up the menu to display the yellow menu-fade and then dismissing it, the effect is much more obvious.

This only seems to happen with ratios between 4:3 and 16:10. That's why you cannot see it in fullscreen.

I strongly suspect there's a lot of relation between this bug and this bug, and after some time I've started suspecting that the clean-scaling code may be involved. (Can we just purge this mess? >_<)

Sadly not. Since it's exposed to ZScript and all of the menu and the intermission screens depend on it, it's there to stay.
The clean scaling itself is not the problem, I think, but some of this old code is full of bad assumptions of what constitutes a widescreen display and what not and is probably making some bad decisions.