Editor scroll bar's gutter don't reach its ends

[kleonc]

Godot version

v4.2.dev2.official [da81ca6], v4.1.1.stable.official [bd6af8e], v4.0.3.stable.official [5222a99]

System information

N/A

Issue description

When dragging an in-editor scrollbar there's still a visible gap even when dragged to one of its ends.

Comparison with v3.5.2.stable.official [170ba33] (from Project Manager):

Steps to reproduce

Try dragging any (?) scrollbar in the editor.

Minimal reproduction project

N/A

[atlas-wheatear]

Confirmed on 4.0, MacOS.

[atlas-wheatear]

The first time this bug appeared was in 4.0-beta15. It was not present in any (pre-)release before this.

Interestingly, the bug presents on as in the issue on 4.0-beta16 and later, but is slightly different on 4.0-beta15.

It scrolls fully on one side, but not the other!

[atlas-wheatear]

Until I can either:

1. work out my errors on trying to compile an unstable branch for MacOS, using vulkan
2. provision a Linux machine somehow

I guess I'll just have to eyeball the changes. If anybody else wants to humour me, here's the diff.

[atlas-wheatear]

Running git bisect, compiling at each step, and manually testing the artifact:

$ git bisect bad
752402cf354a105496ed9a86038f83f56d0706fd is the first bad commit

Here is the commit on the GitHub repo