[gnome-software: 2/7] gs-app: Clarify documentation/annotations for version history

[Philip Withnall <pwithnall src gnome org>]

commit 39a867bd5e6f8558f758cee9d0eebd993ecb2c16
Author: Philip Withnall <pwithnall endlessos org>
Date:   Thu Apr 29 15:45:33 2021 +0100

    gs-app: Clarify documentation/annotations for version history
    
    This clarifies the documentation for the existing behaviour.
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>
    
    Helps: #1227

 lib/gs-app.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)
---
diff --git a/lib/gs-app.c b/lib/gs-app.c
index ef1733987..89ad33470 100644
--- a/lib/gs-app.c
+++ b/lib/gs-app.c
@@ -129,7 +129,7 @@ typedef struct
        GsPluginAction           pending_action;
        GsAppPermissions         permissions;
        gboolean                 is_update_downloaded;
-       GPtrArray               *version_history; /* (element-type AsRelease) */
+       GPtrArray               *version_history; /* (element-type AsRelease) (nullable) (owned) */
 } GsAppPrivate;
 
 enum {
@@ -5349,7 +5349,8 @@ gs_app_set_update_permissions (GsApp *app, GsAppPermissions update_permissions)
  * Gets the list of past releases for an application (including the latest
  * one).
  *
- * Returns: (element-type AsRelease) (transfer none): a list
+ * Returns: (element-type AsRelease) (transfer none) (nullable): a list, or
+ *     %NULL if the version history is not known
  *
  * Since: 40
  **/
@@ -5364,8 +5365,8 @@ gs_app_get_version_history (GsApp *app)
 /**
  * gs_app_set_version_history:
  * @app: a #GsApp
- * @version_history: (element-type AsRelease): a set of entries representing
- *   the version history
+ * @version_history: (element-type AsRelease) (nullable): a set of entries
+ *   representing the version history, or %NULL if none are known
  *
  * Set the list of past releases for an application (including the latest one).
  *