Qt + Wayland + QRubberBand bug with fractional scaling

Repro of a Qt bug on Fedora 40, Qt 6.7.0. 

The rubberband widget leaves pixels behind when these three conditions are true:
1. running on Wayland
2. The display is scaled to 125%
3. the window is maximized (full-screen).

This doesn't happen when scaled 100%, 150%, 175%, or 200%, when the window is any other size (it has to be full-screen). 

It doesn't happen on MacOS (at any scaling factor). 

It doesn't happen on X11 (tested at scaling factor 100% and 200%, I don't have a setup where I can try 125% on X11)

I suspect something is up with how painting and clipping is interacting with fractional scaling. While I happened to find this with the rubberband widget, when I looked at the source code for that widget it didn't seem to be doing anything particularly exotic, so I suspect a bug deeper in the system.

I put together a repro program with a screen capture video here: https://github.com/bradymontz/qt-bug-repro