Description

Enhanced pagination of the query block throws notices if the query ID is not defined.

Notice: Undefined index: queryId in .../gutenberg/build/block-library/blocks/query.php on line 150
Notice: Undefined index: queryId in .../gutenberg/build/block-library/blocks/query.php on line 25
Notice: Undefined index: queryId in .../gutenberg/build/block-library/blocks/query.php on line 170

In the Site Editor, it appears this is prevented from happening, so the issue only occurs if the incorrect markup is used in the files of a distributed theme.

I think if the queryId is not defined, then enhanced pagination can be prevented. Generating a queryId could work but may lead to collisions if there are two queries on the page and one of them has the value defined.

Step-by-step reproduction instructions

1. Enabled debug mode in your wp-config file:

   define( 'WP_DEBUG', true );
   define( 'WP_DEBUG_LOG', true );
   define( 'WP_DEBUG_DISPLAY', true );

2. Download and activate peters-sample-theme.zip which contains bad markup in templates/index.html
3. Visit the theme on the front end of the site.
4. Observe the notices thrown

Screenshots, screen recording, code snippet

Stack trace attached, it's quite a lot because it's generated with xdebug enabled.

debug.log

Environment info

• WordPress trunk (6.5-alpha @ https://github.com/wordPress/wordpress/commits/cc0246c154bc090bc95849f27a2747b3e524f116 )
• Gutenberg trunk @ 929a37d

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