Error on line 1894 ..administrator/components/com_civicrm/civicrm/CRM/Report/Form.php

Warning: strlen() expects parameter 1 to be string, array given in /<joomla root>/administrator/components/com_civicrm/civicrm/CRM/Report/Form.php on line 1894 when running a relationship report. Examination using a debugger shows this code:
default:
if ($value !== NULL && strlen($value) > 0) {
if (isset($field['clause'])) { // FIXME: we not doing escape here. Better solution is to use two // different types - data-type and filter-type $clause = $field['clause']; }
else {
$value = CRM_Utils_Type::escape($value, $type);
$sqlOP = $this->getSQLOperator($op);
if ($field['type'] == CRM_Utils_Type::T_STRING) {
$value = "'{$value}'";
}
$clause = "( {$field['dbAlias']} $sqlOP $value )";
}
}
break;

$value can be an array of integers. From the comments it looks as though this piece of code needs some attention. It may be that this is already happening.