[gtk+] gdk_rgba_parse : do not segfault on null string

[Pierre-Yves Luyten <pyluyten src gnome org>]

commit dce69904d8451f2f8f3c827bdf676d2eb08d898a
Author: Pierre-Yves Luyten <py luyten fr>
Date:   Wed Aug 27 23:14:15 2014 +0200

    gdk_rgba_parse : do not segfault on null string

 gdk/gdkrgba.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/gdk/gdkrgba.c b/gdk/gdkrgba.c
index 66d0bd4..43195dd 100644
--- a/gdk/gdkrgba.c
+++ b/gdk/gdkrgba.c
@@ -166,6 +166,9 @@ gdk_rgba_parse (GdkRGBA     *rgba,
   gchar *str = (gchar *) spec;
   gchar *p;
 
+  g_return_val_if_fail (spec != NULL, FALSE);
+
+
   if (strncmp (str, "rgba", 4) == 0)
     {
       has_alpha = TRUE;