wp-admin/includes/upgrade.php:2313Executes changes made in WordPress 5.9.0.
function upgrade_590() { global $wp_current_db_version; if ( $wp_current_db_version < 51917 ) { $crons = _get_cron_array(); if ( $crons && is_array( $crons ) ) { // Remove errant `false` values, see #53950, #54906. $crons = array_filter( $crons ); _set_cron_array( $crons ); } }}Introduced in 5.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/upgrade.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.