Better fix.

module/VuFindSearch/src/VuFindSearch/Backend/BrowZine/Backend.php

@@ -107,8 +107,10 @@ class Backend extends AbstractBackend
                 $e
             );
         }
+        // Use array_values and array_filter to strip any nulls out of the
+        // response (these are present sometimes due to an apparent API bug)
         $results = isset($response['data']) && is_array($response['data'])
-            ? $response['data'] : [];
+            ? array_values(array_filter($response['data'])) : [];
         $collection = $this->createRecordCollection(
             [
                 'offset' => $offset,

module/VuFindSearch/src/VuFindSearch/Backend/BrowZine/Response/RecordCollectionFactory.php

@@ -100,9 +100,7 @@ class RecordCollectionFactory implements RecordCollectionFactoryInterface
         }
         $collection = new $this->collectionClass($response);
         foreach ($response['data'] as $doc) {
-            if (isset($doc['id'])) {
-                $collection->add(call_user_func($this->recordFactory, $doc));
-            }
+            $collection->add(call_user_func($this->recordFactory, $doc));
         }
         return $collection;
     }