TYPO3 Core

Following form configuration makes an error:

'checkfield' => array(
…
),
'sub_checkfield_1' => array(
'displayCond' => 'FIELD:checkfield:REQ:true',
…
),
'sub_checkfield_2' => array(
'displayCond' => 'FIELD:checkfield:REQ:true',
…
),
'sub_checkfield_3' => array(
'displayCond' => 'FIELD:checkfield:REQ:true',
…
),
…
'palettes' => array(
'5' => array('showitem' => 'sub_checkfield_1, --linebreak--, sub_checkfield_2, sub_checkfield_3'),
),

PHP Warning: implode() [function.implode]: Argument must be an array in […]/typo3_4.4.dev/t3lib/class.t3lib_tceforms.php line 5108

If no --linebreak-- is set, than it works. It works also, if sub_checkfields have no displayCond.

Easy workaround:
t3lib_tceforms.php line 5108
replace: $out .= implode($iRow[$i]);
with: $out .= @implode($iRow[$i]);

lg arno

(issue imported from #M16498)