Image Block: hyperlinks added to Image blocks without http(s) prefix append to page/page slug

[villanovachile]

Steps to reproduce

1. Create new post or page
2. Add an image block, and insert an image
3. Add link to image block, using a URL without http:// or https://. An example is shown here:
   
   Image Link: https://d.pr/i/s2mQwi

What I expected

I expected the image to link to automattic.com and intuitively account for the lack of the https:// prefix

What happened instead

The URL entered appends to the end of the post/page slug:

Image Link: https://d.pr/i/tgNXAE

Clicking on the image results in a 404

Browser / OS version

Browser: Chrome & Safari
OS: macOS 10.15.6

Context / Source

There was a site with multiple 404 errors from viewers (18808537-hc). We determined this was because they added their site URL as hyperlinks to image blocks, they were adding it as www.siteurl.com, which appended the URL to the end of the page/post slug.

There were 480 instances of these hyperlinks, which was resolved using search & replace

It should be noted that this issue occurs on both Simple, Atomic, and self hosted. This issue does NOT occur in the classic editor; it automatically translates www.siteurl.com to https://siteurl.com

[davipontesblog]

@kwight is this something that should be transferred to the Gutenberg project repo in core, or would this be something we could "fix" in Dotcom?

[kwight]

Correct, if it can be replicated in Gutenberg, then it should be there. It sounds like a duplicate of WordPress/gutenberg#6841 (comment).

[davipontesblog]

Correct, if it can be replicated in Gutenberg, then it should be there. It sounds like a duplicate of WordPress/gutenberg#6841 (comment).

Sounds good. Moving this back to the HE triaging board to see if this can be repro'd on a vanilla WordPress install + Gutenberg - if so, this can be moved to the Gutenberg repo: https://github.com/WordPress/gutenberg/issues

[mrfoxtalbot]

I can reproduce this on a local WordPress.org, with and without the Gutenberg plugin (Version 10.3.1). I have moved it here WordPress/gutenberg#31168