TYPO3 Core

..because "$isActive = strcmp($def['content'],'');" is never true because "$def['content']" is never empty.

Solution:
t3lib_tceforms::getMainFields() {
if ($TCA[$table]['columns'][$theField]) {
$sFieldPal='';

if ($parts[2] && !isset($this->palettesRendered[$this->renderDepth][$table][$parts[2]]))    {
                                    $sFieldPal=$this->getPaletteFields($table,$row,$parts[2]);
                                    $this->palettesRendered[$this->renderDepth][$table][$parts[2]] = 1;
                                }
                                $sField = $this->getSingleField($table,$theField,$row,$parts[1],0,$parts[3],$parts[2]);

if ($sField)    { 
                                    $sField.= $sFieldPal;
/*+*/                                    $out_array_meta[$out_sheet]['elementFound'] = true;
                                }

$out_array[$out_sheet][$out_pointer].= $sField;
                            } elseif ($theField=='--div--')    {
...
...
            // Return the imploded $out_array:
        if ($out_sheet>0)    {    // There were --div-- dividers around...

// Create parts array for the tab menu:
            $parts = array();
            foreach ($out_array as $idx => $sheetContent)    {
                if ($out_array_meta[$idx]['title'] == 'Collegium') {
                    #print_r($sheetContent);
                    echo count($sheetContent);
                    echo $out_array_meta[$idx]['title']."<br /><br />";
                }

$parts[] = array(
                    'label' => $out_array_meta[$idx]['title'],
/*modified*/        'content' => (!$out_array_meta[$idx]['elementFound'] ? '': '<table border="0" cellspacing="0" cellpadding="0" width="100%">'.
                            implode('',$sheetContent).
                        '</table>'

);
            }
...
}

The $sheetContent is never realy empty, so I could not use empty($sheetContent). The solution is additonal var which is set true if there is a "real" element.

In the template::getDynTabMenu() instead of the A-tag there should be span with some styles ;)

(issue imported from #M6259)