[libgit2-glib] ggit-revision-walker.c: Fix return annotations

[Igor Gnatenko <ignatenko src gnome org>]

commit 9b528ec89ee174fd10e08cea49df1c60bb2732b4
Author: Brian C. Lane <bcl redhat com>
Date:   Wed Aug 30 12:07:25 2017 -0700

    ggit-revision-walker.c: Fix return annotations
    
    Add (nullable) where needed.

 libgit2-glib/ggit-revision-walker.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/libgit2-glib/ggit-revision-walker.c b/libgit2-glib/ggit-revision-walker.c
index 1b81a7c..034b67d 100644
--- a/libgit2-glib/ggit-revision-walker.c
+++ b/libgit2-glib/ggit-revision-walker.c
@@ -178,7 +178,7 @@ ggit_revision_walker_initable_iface_init (GInitableIface *iface)
  * it is possible to have several revision walkers in
  * several different threads walking the same repository.
  *
- * Returns: (transfer full): a new #GgitRevisionWalker.
+ * Returns: (transfer full) (nullable): a new #GgitRevisionWalker or %NULL.
  */
 GgitRevisionWalker *
 ggit_revision_walker_new (GgitRepository  *repository,
@@ -503,7 +503,7 @@ ggit_revision_walker_hide_head (GgitRevisionWalker  *walker,
  *
  * The revision walker is reset when the walk is over.
  *
- * Returns: (transfer full): the next commit from the revision walk.
+ * Returns: (transfer full) (nullable): the next commit from the revision walk or %NULL.
  */
 GgitOId *
 ggit_revision_walker_next (GgitRevisionWalker  *walker,
@@ -555,7 +555,7 @@ ggit_revision_walker_set_sort_mode (GgitRevisionWalker *walker,
  *
  * Gets the repository on which this walker is operating.
  *
- * Returns: (transfer none): the repository on which this walker is operating.
+ * Returns: (transfer none) (nullable): the repository on which this walker is operating or %NULL.
  */
 GgitRepository *
 ggit_revision_walker_get_repository (GgitRevisionWalker *walker)