Unlinking Submenu block causes empty href attribute on front of site

[getdave]

Description

Unlinking Submenu block causes empty href attribute on front of site.

Step-by-step reproduction instructions

1. Add Nav block.
2. Add Submenu with a link and add one item inside the submenu.
3. Click on Submenu block and click the link icon.
4. Remove the link from the block using the "Unlink" icon in the Link UI.
5. Publish post.
6. Switch to front of site and see empty href on the submenu item in the Nav.

Screenshots, screen recording, code snippet

Environment info

No response

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

[carolinan]

Hi,
What is the expected result? I mean, what change needs to be implemented, should the whole link be removed, and only text displayed?

[getdave]

I don't have the answer to that at this stage. An empty href is invalid so we'd need to decide on the most appropriate markup and / or behaviour.

[aristath]

Hmmm if empty we could make it #. Would that make sense?

[getdave]

I looked into this some more. I turns out it's valid to have a elements without an href.

The href attribute on a and area elements is not required; when those elements do not have href attributes they do not create hyperlinks.

I've created a PR which conditionally adds the href depending on whether it's not empty.

#44337