[gtk/bilelmoussaoui/g-i: 4/5] g-i: Mark get_print_settings as nullable

[Bilal Elmoussaoui <bilelmoussaoui src gnome org>]

commit e6322e177eecda08152fe15734fa2c253b653747
Author: Bilal Elmoussaoui <belmouss redhat com>
Date:   Fri Feb 11 12:07:54 2022 +0100

    g-i: Mark get_print_settings as nullable
    
    Fixes https://github.com/gtk-rs/gtk4-rs/issues/880

 gtk/gtkpagesetupunixdialog.c | 4 ++--
 gtk/gtkprintoperation.c      | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkpagesetupunixdialog.c b/gtk/gtkpagesetupunixdialog.c
index 7bb9ed305f..1539d25f3d 100644
--- a/gtk/gtkpagesetupunixdialog.c
+++ b/gtk/gtkpagesetupunixdialog.c
@@ -898,7 +898,7 @@ set_active_printer (GtkPageSetupUnixDialog *dialog,
 /**
  * gtk_page_setup_unix_dialog_set_print_settings:
  * @dialog: a `GtkPageSetupUnixDialog`
- * @print_settings: a `GtkPrintSettings`
+ * @print_settings: (nullable): a `GtkPrintSettings`
  *
  * Sets the `GtkPrintSettings` from which the page setup dialog
  * takes its values.
@@ -935,7 +935,7 @@ gtk_page_setup_unix_dialog_set_print_settings (GtkPageSetupUnixDialog *dialog,
  *
  * Gets the current print settings from the dialog.
  *
- * Returns: (transfer none): the current print settings
+ * Returns: (transfer none) (nullable): the current print settings
  **/
 GtkPrintSettings *
 gtk_page_setup_unix_dialog_get_print_settings (GtkPageSetupUnixDialog *dialog)
diff --git a/gtk/gtkprintoperation.c b/gtk/gtkprintoperation.c
index 7957d42485..d3a7be011e 100644
--- a/gtk/gtkprintoperation.c
+++ b/gtk/gtkprintoperation.c
@@ -1515,7 +1515,7 @@ gtk_print_operation_set_print_settings (GtkPrintOperation *op,
  * [method@Gtk.PrintOperation.set_print_settings] or
  * [method Gtk PrintOperation run] have been called.
  *
- * Returns: (transfer none): the current print settings of @op.
+ * Returns: (transfer none) (nullable): the current print settings of @op.
  **/
 GtkPrintSettings *
 gtk_print_operation_get_print_settings (GtkPrintOperation *op)