render_block does not render innerblocks when used explicitly

[yashjawale]

When using render_blocks explicitly, it doesn't render the nested blocks if they don't have any innerContent defined in them.

I believe this shouldn't be the case as some parent blocks like core/column shouldn't won't necessarily have innerContent when other blocks are present inside them.

For example, this doesn't render the content of the nested paragraph blocks

<?php
$first_column_blocks = [
        [
                'blockName' => 'core/paragraph',
                'attrs' => [],
                'innerBlocks' => [],
                'innerHTML' => '<p>This is the first column demo content.</p>',
                'innerContent' => [
                        '<p>This is the first column demo content.</p>',
                ],
        ],
];

$second_column_blocks = [
        [
                'blockName' => 'core/paragraph',
                'attrs' => [],
                'innerBlocks' => [],
                'innerHTML' => '<p>This is the second column demo content.</p>',
                'innerContent' => [
                        '<p>This is the second column demo content.</p>',
                ],
        ],
];

$column_layout_block = [
        'blockName' => 'core/columns',
        'attrs' => [],
        'innerBlocks' => [
                [
                        'blockName' => 'core/column',
                        'attrs' => [],
                        'innerBlocks' => $first_column_blocks
                ],
                [
                        'blockName' => 'core/column',
                        'attrs' => [],
                        'innerBlocks' => $second_column_blocks
                ],
        ]
];

For markup generated by Gutenberg, there is some innerContent generated hence, it doesn't the same issue. But I don't think a developer is expected to pass this content in explicitly [demonstrated in linked image]

More info present in Gutenberg ticket linked below

---

This issue was originally reported by Andreas Lindahl as an Issue on Gutenberg repository
​https://github.com/WordPress/gutenberg/issues/69307

[yashjawale]

innerContent generated by same layout created in Gutenberg editor instead

[yashjawale]

I've narrowed down the cause to innerContent check in render() method of class-wp-block.php

I'll be happy to work on a patch for this issue if this isn't expected behavior

Ref: ​https://github.com/yashjawale/wordpress-develop/blob/fc41a79118c10a897e0b29b97d40bea110cebafc/src/wp-includes/class-wp-block.php#L534