Priority: P2: Important
Affects Version/s: 5.15.2, 6.0.3, 6.1.0 Beta3
Fix Version/s: None
Environment:The easiest way to reproduce is to have 2 monitors. Move the test application to the second one, put the DPI settings dialog on the first one. This way the application is not being obstructed and you can easily see the issue.
Steps to reproduce:
- Set the DPI scale on the monitor to 100%
- Start the attached demo application (or virtually any QWidget-based example application)
- Put the window into full screen (Toggle full screen mode button)
- Set the DPI scale on the monitor to 150%
- Set the DPI scale on the monitor to 100% again
Expected result: the window resizes properly
Actual result: the window has the same size as it was on 150% and put to the top left corner of the screen. The widgets are not re-drawn until I hover over them. In addition, the window falls into a "half-full screen" state when it doesn't have a `Qt::WindowFullScreen` flag, but it can't be resized (and other normal-state stuff doesn't work, e.g. handling WM_NCHITTEST to tell where the window can be resized etc.). It can only be brought back to normal if I call `showFullScreen()` and `showNormal()` again.
Even Qt Creator breaks (see video "2021-04-14 14-11-56.mp4")