fix(management) Fix multivalue support in Column class

Moved up from LinkColumn

issue #5135

include/management/columns/class_Column.inc

@@ -175,6 +175,15 @@ class Column
     $value = $this->getAttributeValue($entry);
     if ($value == '') {
       return ' ';
+    } elseif (is_array($value)) {
+      $value = array_map(
+        function ($v)
+        {
+          return htmlentities($v, ENT_COMPAT, 'UTF-8');
+        },
+        $value
+      );
+      return implode("<br/>\n", $value);
     } else {
       return htmlentities($value, ENT_COMPAT, 'UTF-8');
     }

include/management/columns/class_LinkColumn.inc

@@ -25,23 +25,7 @@ class LinkColumn extends Column
 {
   function renderCell(ListingEntry $entry)
   {
-    $value = $this->getAttributeValue($entry);
-    if ($value == '') {
-      return ' ';
-    } else {
-      if (is_array($value)) {
-        $value = array_map(
-          function ($v)
-          {
-            return htmlentities($v, ENT_COMPAT, 'UTF-8');
-          },
-          $value
-        );
-        return $this->renderLink($entry, implode("<br/>\n", $value));
-      } else {
-        return $this->renderLink($entry, htmlentities($value, ENT_COMPAT, 'UTF-8'));
-      }
-    }
+    return $this->renderLink($entry, parent::renderCell($entry));
   }
 
   protected function renderLink(ListingEntry $entry, $htmlValue)