g-i: mark get_selected_printer as nullable

There is no selected printer if the user closes the dialog
Fixes https://github.com/gtk-rs/gtk4-rs/issues/882

diff --git a/gtk/gtkprintunixdialog.c b/gtk/gtkprintunixdialog.c
index 6c1ff5c2609b98959b18bb7e690dc6239927847c..d6c98d41ecc4a9aff9017a2de09a6f8de891692a 100644 (file)
--- a/gtk/gtkprintunixdialog.c
+++ b/gtk/gtkprintunixdialog.c
@@ -3078,7 +3078,7 @@ gtk_print_unix_dialog_new (const char *title,
  *
  * Gets the currently selected printer.
  *
- * Returns: (transfer none): the currently selected printer
+ * Returns: (transfer none) (nullable): the currently selected printer
  */
 GtkPrinter *
 gtk_print_unix_dialog_get_selected_printer (GtkPrintUnixDialog *dialog)