refs #16624 [fid]

* handle multi-valued issue attribute in publication meta data
* normalize publication issue only if actually set

module/fid/src/Hydrator/OrderHydrator.php

@@ -44,6 +44,10 @@ class OrderHydrator extends AbstractHydrator {
         $url = $data['url'];
         /* Collect special journal data used for subito-article*/
         $publishedIn = $driver->tryMethod('getPublishedIn');
+        if (isset($publishedIn['issue'])) {
+            $publishedIn['issue'] = is_string($publishedIn['issue'])
+                ? $publishedIn['issue'] : implode(', ', $publishedIn['issue']);
+        }
 
         $record = compact(
             'id',