TYPO3 Core

I consider the following fact confusing, especially, because it's not documented (or I didn't find it in documentation).

The following in TCA works even if nonIDvalues are set by &tx_hgwstaff_processSortings->main. If the items-Part is left out, it won't.
-----------------
"fieldname" => Array (
"config" => Array (
"type" => "select",
'items' => Array (
Array('', 0),
),
"allowNonIdValues" => 1,
"itemsProcFunc" =>"&tx_hgwstaff_processSortings->main",
"maxitems" => 5,
-----------------
It doesn't work if setup is:
-----------------
"fieldname" => Array (
"config" => Array (
"type" => "select",
//Here is no items-Initialization necessary, because it's done by itemsProcFunc
"allowNonIdValues" => 1,
"itemsProcFunc" =>"&tx_hgwstaff_processSortings->main",
"maxitems" => 5,
-----------------

The reason seams to be in class.t3lib_transferdata.php:
[...]
function renderRecord_selectProc($data,$fieldConfig,$TSconfig,$table,$row,$field) {
global $TCA;

// Initialize:
                $elements = t3lib_div::trimExplode(',',$data,1);        // Current data set.
                $dataAcc=array();       // New data set, ready for interface (list of values, rawurlencoded)

// For list selectors (multi-value):
                if (intval($fieldConfig['config']['maxitems'])>1)       {

// Add regular elements:
                        if (is_array($fieldConfig['config']['items']))  { //Process of Items is only called, if the array is initialized.
                                $fieldConfig['config']['items'] = $this->procesItemArray($fieldConfig['config']['items'], $fi                                foreach($fieldConfig['config']['items'] as $pvpv)       {
                                        foreach($elements as $eKey => $value)   {
                                                if (!strcmp($value,$pvpv[1]))   {
                                                        $dataAcc[$eKey]=rawurlencode($pvpv[1]).'|'.rawurlencode($pvpv[0]);
                                                }
                                        }
                                }
                        }

[...]
(issue imported from #M2694)