[mutter/wip/tintou/add-nullable: 1/2] workspace-manager: get_workspace_by_index can return NULL

[Corentin Noël <corentinnoel src gnome org>]

commit a617c7dfeed31413f072ee1b5d1652f664bdd49c
Author: Corentin Noël <corentin noel collabora com>
Date:   Mon Nov 18 18:19:02 2019 +0100

    workspace-manager: get_workspace_by_index can return NULL
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/941

 src/core/meta-workspace-manager.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/core/meta-workspace-manager.c b/src/core/meta-workspace-manager.c
index 4f668e041..36d0b9bcd 100644
--- a/src/core/meta-workspace-manager.c
+++ b/src/core/meta-workspace-manager.c
@@ -294,8 +294,8 @@ meta_workspace_manager_get_n_workspaces (MetaWorkspaceManager *workspace_manager
  * index. It's valid to call this function with an out-of-range index and it
  * will robustly return %NULL.
  *
- * Return value: (transfer none): the workspace object with specified index, or %NULL
- *   if the index is out of range.
+ * Return value: (transfer none) (nullable): the workspace object with specified
+ *   index, or %NULL if the index is out of range.
  */
 MetaWorkspace *
 meta_workspace_manager_get_workspace_by_index (MetaWorkspaceManager *workspace_manager,