Users can scroll off the bottom of the block editor into a forbidden void when searching in the inserter

[talldan]

Step-by-step reproduction instructions

1. Open the site editor (not sure if it happens in the post editor)
2. Open the inserter
3. Enter the search term 'List'

Expected: The inserter scrollbar expands, but the canvas scroll bar isn't affected
Actual: The canvas scrollbar expands allowing users to scroll down into empty space

Screenshots, screen recording, code snippet

Kapture.2023-12-06.at.13.16.11.mp4

Environment info

Tested against latest Gutenberg trunk (d1d0b2a)
Mac OS / Brave

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

[colorful-tones]

Confirmed in Chrome Version 120.0.6099.109 with latest Gutenberg trunk 9879b85

[colorful-tones]

Also, this happens in the post editor as well. It is not isolated to the Site Editor.

[colorful-tones]

This is definitely browser based and bug exists in Safari Version 17.2 (19617.1.17.11.9) too, but does not affect Firefox 120. I'm doing some debugging to try and decipher what has changed in Blink/webkit browsers, while accounting to make sure all will work nicely on mobile (iOS). I think I've traced it down to an overflow issue. There is this note from Safari 17.2 Release Notes, which feels like a solid lead: https://developer.apple.com/documentation/safari-release-notes/safari-17_2-release-notes#Scrolling.

I'm feeling like it is pointing to styling here: https://github.com/WordPress/gutenberg/blob/trunk/packages/interface/src/components/interface-skeleton/style.scss#L45-L137

[colorful-tones]

I think I've got a fix in place #57127, but it could use some thorough cross browser testing. I only had time to fix and verify in Chrome 120.

[andrewserong]

Thanks for fixing this one up @colorful-tones! 🎉