[nautilus] extension: Add some missing nullable annotations

[António Fernandes <antoniof src gnome org>]

commit 960ef5fb85fdcee28c3ae45a51bf1509f8578c70
Author: Aaron Jacobs <atheriel gmail com>
Date:   Wed Dec 1 10:33:17 2021 -0500

    extension: Add some missing nullable annotations
    
    I've generally verified that these are nullable by looking elsewhere in
    the source.

 libnautilus-extension/nautilus-column-provider.h          | 2 +-
 libnautilus-extension/nautilus-file-info.h                | 4 ++--
 libnautilus-extension/nautilus-location-widget-provider.h | 2 +-
 libnautilus-extension/nautilus-menu.h                     | 4 ++--
 libnautilus-extension/nautilus-property-page-provider.h   | 2 +-
 5 files changed, 7 insertions(+), 7 deletions(-)
---
diff --git a/libnautilus-extension/nautilus-column-provider.h 
b/libnautilus-extension/nautilus-column-provider.h
index a5a646889..3cf15475a 100644
--- a/libnautilus-extension/nautilus-column-provider.h
+++ b/libnautilus-extension/nautilus-column-provider.h
@@ -80,7 +80,7 @@ struct _NautilusColumnProviderInterface
  * nautilus_column_provider_get_columns:
  * @provider: a #NautilusColumnProvider
  *
- * Returns: (element-type NautilusColumn) (transfer full): the provided #NautilusColumn objects
+ * Returns: (nullable) (element-type NautilusColumn) (transfer full): the provided #NautilusColumn objects
  */
 GList *nautilus_column_provider_get_columns (NautilusColumnProvider *provider);
 
diff --git a/libnautilus-extension/nautilus-file-info.h b/libnautilus-extension/nautilus-file-info.h
index afd3412de..baa8c8d3b 100644
--- a/libnautilus-extension/nautilus-file-info.h
+++ b/libnautilus-extension/nautilus-file-info.h
@@ -230,7 +230,7 @@ void              nautilus_file_info_invalidate_extension_info (NautilusFileInfo
  * nautilus_file_info_lookup:
  * @location: the location for which to look up a corresponding #NautilusFileInfo object
  *
- * Returns: (transfer full): a #NautilusFileInfo
+ * Returns: (nullable) (transfer full): a #NautilusFileInfo
  */
 NautilusFileInfo *nautilus_file_info_lookup                (GFile *location);
 /**
@@ -244,7 +244,7 @@ NautilusFileInfo *nautilus_file_info_create                (GFile *location);
  * nautilus_file_info_lookup_for_uri:
  * @uri: the URI to lookup the file info for
  *
- * Returns: (transfer full): a #NautilusFileInfo
+ * Returns: (nullable) (transfer full): a #NautilusFileInfo
  */
 NautilusFileInfo *nautilus_file_info_lookup_for_uri        (const char *uri);
 /**
diff --git a/libnautilus-extension/nautilus-location-widget-provider.h 
b/libnautilus-extension/nautilus-location-widget-provider.h
index 4780cfffd..2b04ba57e 100644
--- a/libnautilus-extension/nautilus-location-widget-provider.h
+++ b/libnautilus-extension/nautilus-location-widget-provider.h
@@ -85,7 +85,7 @@ struct _NautilusLocationWidgetProviderInterface
  * @uri: the URI of the location
  * @window: parent #GtkWindow
  *
- * Returns: (transfer none): the location widget for @provider at @uri
+ * Returns: (transfer none) (nullable): the location widget for @provider at @uri
  */
 GtkWidget *nautilus_location_widget_provider_get_widget (NautilusLocationWidgetProvider *provider,
                                                          const char                     *uri,
diff --git a/libnautilus-extension/nautilus-menu.h b/libnautilus-extension/nautilus-menu.h
index d699e1c95..c9f05338c 100644
--- a/libnautilus-extension/nautilus-menu.h
+++ b/libnautilus-extension/nautilus-menu.h
@@ -88,7 +88,7 @@ void              nautilus_menu_append_item      (NautilusMenu     *menu,
  * nautilus_menu_get_items:
  * @menu: a #NautilusMenu
  *
- * Returns: (element-type NautilusMenuItem) (transfer full): the provided #NautilusMenuItem list
+ * Returns: (nullable) (element-type NautilusMenuItem) (transfer full): the provided #NautilusMenuItem list
  */
 GList            *nautilus_menu_get_items        (NautilusMenu     *menu);
 /**
@@ -103,7 +103,7 @@ void              nautilus_menu_item_list_free   (GList            *item_list);
  * @name: the identifier for the menu item
  * @label: the user-visible label of the menu item
  * @tip: the tooltip of the menu item
- * @icon: the name of the icon to display in the menu item
+ * @icon: (nullable): the name of the icon to display in the menu item
  *
  * Creates a new menu item that can be added to the toolbar or to a contextual menu.
  *
diff --git a/libnautilus-extension/nautilus-property-page-provider.h 
b/libnautilus-extension/nautilus-property-page-provider.h
index 83778f6e5..8c9fe328c 100644
--- a/libnautilus-extension/nautilus-property-page-provider.h
+++ b/libnautilus-extension/nautilus-property-page-provider.h
@@ -90,7 +90,7 @@ struct _NautilusPropertyPageProviderInterface
  * This function is called in the main thread before a property page
  * is shown, so it should return quickly.
  *
- * Returns: (element-type NautilusPropertyPage) (transfer full): A #GList of allocated #NautilusPropertyPage 
items.
+ * Returns: (nullable) (element-type NautilusPropertyPage) (transfer full): A #GList of allocated 
#NautilusPropertyPage items.
  */
 GList *nautilus_property_page_provider_get_pages (NautilusPropertyPageProvider *provider,
                                                   GList                        *files);