Minimum schema version of Drupal 7 required for upgrade to Backdrop.

Upgrades from Drupal 7 to Backdrop require that Drupal 7 be running the most recent version, or the upgrade could fail. We can't check the Drupal 7 version once the update process has begun, so instead we check the schema version of system.module in the system table.


core/includes/, line 18
Backdrop database update API.


define('REQUIRED_D7_SCHEMA_VERSION', '7069')