} else {
$expiryHtml = $this->msg( 'userrights-expiry-none' )->text();
}
+ // T171345: Add a hidden form element so that other groups can still be manipulated,
+ // otherwise saving errors out with an invalid expiry time for this group.
+ $expiryHtml .= Html::Hidden( "wpExpiry-$group",
+ $currentExpiry ? 'existing' : 'infinite' );
$expiryHtml .= "<br />\n";
} else {
$expiryHtml = Xml::element( 'span', null,