reports_user() returns invalid value, causing user.module errors

In reports.module, reports_user() is implemented as a dummy/placeholder function that always returns TRUE. However, the hook_user() API promises to return either an array, or nothing at all. See http://api.drupal.org/api/HEAD/function/hook_user.

user.module calls module_invoke($module, 'user', 'view', $account) in a few places. When $module='reports', the result is a TRUE instead of an array, and subsequent foreach()'s choke on it. As a result, the user edit page is left unusable. The user view page also shows a difficult-to-trace error, but remains usable.