update.php does not invoke hook_requirements('update') in all modules

It doesn't look like hook_requirements() was ever invoked for all modules. I just searched in D5's update.php, and the term "requirements" does not even appear once in there.

Note that with the patch, System module's requirements are checked twice on update.php -- once for the initial update.php bootstrap, which loads system.module only to check fundamental system requirements prior to attempting to update anything; and then once again on update.php's 'info' task/step, in which all modules are loaded for the first time.

I tested this patch by temporarily adding:

function example_requirements($phase = 'runtime') {
  $requirements = array();
  if ($phase == 'update') {
    $requirements['example'] = array(
      'title' => 'Error title',
      'value' => 'Error value',
      'severity' => REQUIREMENT_ERROR,
    );
  }
  return $requirements;
}

...which successfully prevented me from updating.

Given that module requirements can heavily change when upgrading to or updating within D7, this is a pretty major bug.

Thanks, fixed that comment.

Good catch, thanks!