wp-includes/blocks.php:2146Callback used for regular expression replacement in filter_block_content().
$matchesarraystringfunction _filter_block_content_callback( $matches ) { return '<!--' . rtrim( $matches[1], '-' ) . '-->';}Introduced in 6.2.1. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/blocks.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.