[glib/wip/mjog/utf8-norm-missing-nullable-annotation] g_utf8_normalize: Doc comment return missing nullable annotation

[Michael Gratton <mjog src gnome org>]

commit 995af0fc91da22f6c2bf81302e8dadcfe2e24d91
Author: Michael Gratton <mike vee net>
Date:   Wed Jun 26 09:40:12 2019 +1000

    g_utf8_normalize: Doc comment return missing nullable annotation
    
    The return value for g_utf8_normalize may be null, but the return type
    is not annotated as such. This is important for language bindings for
    langs that are about nullability, such as Vala and Haskell.

 glib/gunidecomp.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/glib/gunidecomp.c b/glib/gunidecomp.c
index b85351883..2eb30b38a 100644
--- a/glib/gunidecomp.c
+++ b/glib/gunidecomp.c
@@ -521,9 +521,9 @@ _g_utf8_normalize_wc (const gchar    *str,
  * a legacy encoding or pass it to a system with
  * less capable Unicode handling.
  *
- * Returns: a newly allocated string, that is the
- *   normalized form of @str, or %NULL if @str is not
- *   valid UTF-8.
+ * Returns: (nullable): a newly allocated string, that
+ *   is the normalized form of @str, or %NULL if @str
+ *   is not valid UTF-8.
  **/
 gchar *
 g_utf8_normalize (const gchar    *str,