[gtk: 1/2] print: Free print backends after use

[Matthias Clasen <matthiasc src gnome org>]

commit e68a3a612397f20b41955054882a64ac2cafdbcd
Author: Marek Kasik <mkasik redhat com>
Date:   Mon Jul 11 16:54:36 2022 +0200

    print: Free print backends after use
    
    Print backends loaded in GtkPrintUnixDialog's load_print_backends()
    are not freed later as done in e.g. GtkPageSetupUnixDialog.
    This commit destroys and unref those print backends.
    
    Closes #5019

 gtk/gtkprintunixdialog.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtkprintunixdialog.c b/gtk/gtkprintunixdialog.c
index 14c15264ad..fd23cd9a89 100644
--- a/gtk/gtkprintunixdialog.c
+++ b/gtk/gtkprintunixdialog.c
@@ -942,6 +942,7 @@ static void
 gtk_print_unix_dialog_finalize (GObject *object)
 {
   GtkPrintUnixDialog *dialog = GTK_PRINT_UNIX_DIALOG (object);
+  GList *iter;
 
   unschedule_idle_mark_conflicts (dialog);
   disconnect_printer_details_request (dialog, FALSE);
@@ -967,7 +968,9 @@ gtk_print_unix_dialog_finalize (GObject *object)
   g_clear_pointer (&dialog->waiting_for_printer, (GDestroyNotify)g_free);
   g_clear_pointer (&dialog->format_for_printer, (GDestroyNotify)g_free);
 
-  g_list_free (dialog->print_backends);
+  for (iter = dialog->print_backends; iter != NULL; iter = iter->next)
+    gtk_print_backend_destroy (GTK_PRINT_BACKEND (iter->data));
+  g_list_free_full (dialog->print_backends, g_object_unref);
   dialog->print_backends = NULL;
 
   g_clear_object (&dialog->page_setup_list);