Lots of newlines in REST API rendered content when using block editor

[rmens]

In a post created with the block editor i have the following

<!-- wp:paragraph -->
<p>This is paragraph 1</p>
<!-- /wp:paragraph -->

<!-- wp:paragraph -->
<p>This is paragraph 2</p>
<!-- /wp:paragraph -->

But the REST API renders the content as

"\n<p>This is paragraph 1</p>\n\n\n\n<p>This is paragraph 2</p>\n"

There seem to be 4 newlines between the paragraphs, while there should only be one. When I make the same post in the classic editor, it comes out like this. Which looks more correct.

"<p>This is paragraph 1</p>\n<p>This is paragraph 2</p>\n"

[joyously]

Are the block marker comments being converted to \n?

[rmens]

Hi @joyously, after some more testing this does seem to be the case. Normal HTML-comments like <!-- this is a comment --> don't convert to \n but block markers are.

[TimothyBlynJacobs]

I'm moving this to the Editor component as it is responsible for rendering the raw content, the REST API only applies the the_content filter.

[SergeyBiryukov]

Hi there, welcome back to WordPress Trac!

Thanks for the report, we're already tracking this issue in #46655.