diff -r 5099a34747c4 -r a8faf8757450 ui/gtk/tree.c
--- a/ui/gtk/tree.c	Sun Apr 07 11:26:38 2024 +0200
+++ b/ui/gtk/tree.c	Sun Apr 07 12:36:07 2024 +0200
@@ -616,6 +616,7 @@
         event->userdata = udata;
         event->callback = f;
         event->value = 0;
+        event->customdata = NULL;
 
         g_signal_connect(
                 combobox,