Group block: child group block has multiple inner container div

[t-hamano]

Description

The front-end side will output a container ( .wp-block-group__inner-container ) if the HTML element of the group block is the default div .
When group blocks are nested and the HTML element of the parent block is set to something other than div, the descendant group blocks will output multiple containers.

Step-by-step reproduction instructions

1. Inserts a nested group block.
2. Select something other than a <div> from "HTML Element" in Advanced panel for the parent group block.

Screenshots, screen recording, code snippet

Block List View Example

- Group Block ( main tag)
	- Group Block ( main tag)
		- Group Block ( div tag)

HTML Outpul Result

<main class="wp-block-group">
	<main class="wp-block-group">
		<div class="wp-block-group">
			<div class="wp-block-group__inner-container">
				<div class="wp-block-group__inner-container">
					<div class="wp-block-group__inner-container"></div>
				</div>
			</div>
		</div>
	</main>
</main>

Environment info

No response

Pre-checks

• I have searched the existing issues.
• I have tested with all plugins deactivated except Gutenberg.

[t-hamano]

I suspect that the cause is that the closing tag in the div.wp-block-group__inner-container box of the Group block is being output in the wrong position.

Here's another example.

Step-by-step reproduction instructions

• Inserts a group block.
• Inserts two group blocks in parallel into the parent group block.
• Sets the HTML element of the parent group block to something other than a div tag.

Editor View

Frontend View

[talldan]

This sounds like a similar issue to the one reported here - #34199

[talldan]

I could reproduce the second set of steps. An important caveat is that I think reproducing requires a classic theme. I used Twenty Twenty One. In block based themes the group block omits the inner container.

Editor:

Post:

[davecpage]

@talldan you were correct, the issue was similar to the one on #34199 in that the regexes needed to be adjusted.

[davecpage]

@noisysocks Similar to #34199 would this also need to be ported over to the WordPress core for inclusion in 5.9?

[noisysocks]

The fix #36256 landed in Gutenberg 11.9 which means it's included in WP 5.9.