[gegl] gegl_buffer_get_unlocked: fix a potential dereference of null pointer

[Ãyvind KolÃs <ok src gnome org>]

commit ae2ade7065e9a2b13c9589f01d34ee59b1c6526d
Author: Michael Murà <batolettre gmail com>
Date:   Tue Aug 2 10:46:17 2011 +0200

    gegl_buffer_get_unlocked: fix a potential dereference of null pointer

 gegl/buffer/gegl-buffer-access.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gegl/buffer/gegl-buffer-access.c b/gegl/buffer/gegl-buffer-access.c
index fa37f37..92e7648 100644
--- a/gegl/buffer/gegl-buffer-access.c
+++ b/gegl/buffer/gegl-buffer-access.c
@@ -953,6 +953,8 @@ gegl_buffer_get_unlocked (GeglBuffer          *buffer,
       gegl_buffer_iterate (buffer, NULL, dest_buf, rowstride, FALSE, format, 0);
       return;
     }
+
+  g_return_if_fail (rect);
   if (rect->width == 0 ||
       rect->height == 0)
     {