wp-includes/revision.php:410Save the revisioned meta fields.
$revision_idint$post_idintfunction wp_save_revisioned_meta_fields( $revision_id, $post_id ) { $post_type = get_post_type( $post_id ); if ( ! $post_type ) { return; } foreach ( wp_post_revision_meta_keys( $post_type ) as $meta_key ) { if ( metadata_exists( 'post', $post_id, $meta_key ) ) { _wp_copy_post_meta( $post_id, $revision_id, $meta_key ); } }}Introduced in 6.4.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/revision.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.