Inline formatting toolbar border radius clipping

[stokesman]

Description

The formatting toolbar’s corners are getting a little clipped. It appears to have came about in #64368

Step-by-step reproduction instructions

1. Add an image block
2. Add or focus the caption text
3. Note the formatting toolbar’s clipped corners

Screenshots, screen recording, code snippet

Environment info

• Gutenberg trunk

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

[stokesman]

@jameskoster, you’d perhaps be most wise on how to fix this. I see this in 6.7 beta but not in 6.6 so I think it would qualify for fixing in 6.7. Of course it’s not too critical.

[jameskoster]

Good spot. There are a couple of things happening:

1. This toolbar is wrapped in a Popover, the 4px radius of which is clipping the toolbar.
2. Button groups in this toolbar have a background color, whereas groups in the regular block toolbar do not.

We need to explore updating the toolbar component to align with the new radius scale, but that's a 6.8 thing.

I'll open a PR for 6.7 to address this.