SMTP settings form setDefaultValues does not filter civicrm_preferences by domain_id or is_domain (3.4)

(This affects 3.4 but not 4.1, as 4.1 uses the new CRM_Core_BAO_Setting.)

CRM_Admin_Form_Setting_Smtp::setDefaultValues does this...

$mailingDomain = new CRM_Core_DAO_Preferences();
$mailingDomain->find(true);

...which retrieves any old row from civicrm_preferences. So if the first row retrieved relates to another domain_id, that's what will be used to set the form defaults. Changing the above to...

$mailingDomain = new CRM_Core_DAO_Preferences();
$mailingDomain->domain_id = CRM_Core_Config::domainID( );
$mailingDomain->is_domain = true;
$mailingDomain->find(true);

...fixes it. Patch attached.