[BUGFIX] BE select tree needs to validate minitems

FormEngineValidation configuration was not added in
SelectTreeElement therefore minitems was not validated.

Change-Id: I38fcf1f20c5eeed667bea96130d4295a56790888
Resolves: #70084
Releases: master
Reviewed-on: http://review.typo3.org/43532


Reviewed-by: Frank Nägler <frank.naegler@typo3.org>
Tested-by: Frank Nägler <frank.naegler@typo3.org>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>

typo3/sysext/backend/Classes/Form/Element/SelectTreeElement.php

@@ -143,7 +143,11 @@ class SelectTreeElement extends AbstractFormElement {
 		}
 		$html = '
 			<div class="typo3-tceforms-tree">
-				<input class="treeRecord" type="hidden" name="' . htmlspecialchars($parameterArray['itemFormElName']) . '" id="treeinput' . $id . '" value="' . htmlspecialchars(implode(',', $selectedNodesForApi)) . '" />
+				<input class="treeRecord" type="hidden" '
+					.  $this->getValidationDataAsDataAttribute($config)
+					. ' data-formengine-input-name="' . htmlspecialchars($parameterArray['itemFormElName']) . '"'
+					. ' data-relatedfieldname="' . htmlspecialchars($parameterArray['itemFormElName']) . '"'
+					. ' name="' . htmlspecialchars($parameterArray['itemFormElName']) . '" id="treeinput' . $id . '" value="' . htmlspecialchars(implode(',', $selectedNodesForApi)) . '" />
 			</div>
 			<div id="tree_' . $id . '">