Post Editor: Background issue in non-iframe editor

[t-hamano]

Description

Note: This issue first occurs in WP6.6.

If the post editor is NOT an iframe, e.g. contains a version 2 block, two issues with the background will arise:

• There is not enough space at the bottom of the content
• The background color disappears halfway through

1. There is not enough space at the bottom of the content

There should be 40vh of space reserved, but there is no space at all, which means you cannot click the space below the last block to insert a new block.

WP6.5

Below the last paragraph, there is a padding of 40vh, which you can click to insert a new block.

WP6.6 or the Latest Gutenberg

It looks like there is a little bit of space below the paragraph, but this is the browser default margin, not the editor canvas padding, so clicking here will do nothing.

2. The background color disappears halfway through

WP6.5

The background color fills the entire canvas.

WP6.6 or the Latest Gutenberg

When scrolling down with a lot of content, the background color disappears.

Step-by-step reproduction instructions

• Enable the TT1 theme, which has a more visible background color.
• To make the post editor not an iframe, do one of the following:
  • Activate the Jetpack plugin. This plugin contains version 1 blocks.
  • Change the apiVerson of one of the core blocks to 2 via the following hook:

    function example_filter_metadata_registration( $settings, $metadata ) {
    	if ( 'core/paragraph' === $metadata['name'] ) {
    		$settings['api_version'] = 2;
    	}
    	return $settings;
    };
    add_filter( 'block_type_metadata_settings', 'example_filter_metadata_registration', 10, 2 );

• Access the post editor and enter more content.
• Scroll to the very bottom of the content.

Screenshots, screen recording, code snippet

No response

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

[t-hamano]

I think this is a big issue for WP6.6 so I'll add it to the task board.