Darktable interface misbehaves with displayscaling enabled

Is there an existing issue for this?

• I checked and did not find my issue in the already reported ones

Describe the bug

Using Linux and Gnome when display scaling is enabled (e.g. set to 125% on high dpi screens), the darktable interface does not scale properly. Resizing the sidepanes would sometimes grow the whole window, the whole program window doesn't fit on the screen and every try to resize or shrink it fails or behaves weirdly.

I believe this was introduced with 5.6 - I remember there have been similar issues earlier, when the wayland support was in it's infance, but 5.4 mostly just worked.

Steps to reproduce

1. set display scaling to some value other than 100% - 125% for example
2. launch darktbale
3. notice the whole window and resizing controls do not work as expected

Expected behavior

Well, it should just work or drop a notice about potential mitigations (aside from turning of scaling..)

Logfile | Screenshot | Screencast

Logs can be provided but don't show anything interesting at first glance.

Commit

No response

Where did you obtain darktable from?

distro packaging

darktable version

darktable 5.6.0

What OS are you using?

Linux

What is the version of your OS?

Arch

Describe your system

Up to date Arch, Gnome 50.3, Wayland

Are you using OpenCL GPU in darktable?

Yes

If yes, what is the GPU card and driver?

No response

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

No response

Start by reproducing the issue on Linux with GNOME 50.3 and Wayland at 125% display scaling, then compare darktable 5.6.0 with 5.4 if available. Exercise the launch, window resizing, and side-pane resizing steps; done means the window fits the screen and resizing behaves normally, or the application clearly reports a mitigation.