--- a/program/lib/Roundcube/rcube_imap.php	Thu Oct 09 11:31:41 2025 -0400
+++ b/program/lib/Roundcube/rcube_imap.php	Wed Oct 15 14:06:27 2025 -0400
@@ -332,18 +332,18 @@
      */
     public function set_search_set($set)
     {
-        $set = (array)$set;
-
-        $this->search_string     = $set[0];
-        $this->search_set        = $set[1];
-        $this->search_charset    = $set[2];
-        $this->search_sort_field = $set[3];
-        $this->search_sorted     = $set[4];
-        $this->search_threads    = is_a($this->search_set, 'rcube_result_thread');
-
-        if (is_a($this->search_set, 'rcube_result_multifolder')) {
-            $this->set_threading(false);
-        }
+      $set = (array) $set;
+
+      $this->search_string     = $set[0] ?? null;
+      $this->search_set        = $set[1] ?? null;
+      $this->search_charset    = $set[2] ?? null;
+      $this->search_sort_field = $set[3] ?? null;
+      $this->search_sorted     = $set[4] ?? null;
+      $this->search_threads    = is_a($this->search_set, 'rcube_result_thread');
+
+      if (is_a($this->search_set, 'rcube_result_multifolder')) {
+	$this->set_threading(false);
+      }
     }
 
     /**
@@ -3451,7 +3451,7 @@
 
         $key = $subscription ? 'subscribed' : 'existing';
 
-        if (is_array($this->icache[$key]) && in_array($folder, $this->icache[$key])) {
+        if (is_array($this->icache[$key]??null) && in_array($folder, $this->icache[$key])) {
             return true;
         }