- fixed missing title in hierarchyTree if "title_in_hierarchy" is empty...

- fixed missing title in hierarchyTree if "title_in_hierarchy" is empty (optional index field, was introduced in https://github.com/vufind-org/vufind/commit/d042503cd1b09247effd1f436d9119fc770862c5)

module/VuFind/src/VuFind/Hierarchy/TreeDataSource/Solr.php

@@ -165,14 +165,15 @@ class Solr extends AbstractBase
             ++$count;
             if ($sorting) {
                 $positions = $current->getHierarchyPositionsInParents();
-                $titles = $current->getTitlesInHierarchy();
                 if (isset($positions[$parentID])) {
                     $sequence = $positions[$parentID];
                 }
-                $title = isset($titles[$parentID])
-                    ? $titles[$parentID] : $current->getTitle();
             }
 
+            $titles = $current->getTitlesInHierarchy();
+            $title = isset($titles[$parentID])
+                ? $titles[$parentID] : $current->getTitle();
+
             $this->debug("$parentID: " . $current->getUniqueID());
             $xmlNode = '';
             $isCollection = $current->isCollection() ? "true" : "false";