[gegl] gegl_buffer_sample: fix issue in previous commits bugfixing

[Øyvind Kolås <ok src gnome org>]

commit f340fb84ab929b1dc752860619601109780d9ad7
Author: �yvind Kolås <pippin gimp org>
Date:   Sat Jan 30 14:37:50 2010 +0000

    gegl_buffer_sample: fix issue in previous commits bugfixing

 gegl/buffer/gegl-buffer-access.c  |    1 +
 gegl/buffer/gegl-buffer-private.h |    2 +-
 2 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gegl/buffer/gegl-buffer-access.c b/gegl/buffer/gegl-buffer-access.c
index 25c8b00..82fdfa8 100644
--- a/gegl/buffer/gegl-buffer-access.c
+++ b/gegl/buffer/gegl-buffer-access.c
@@ -1112,6 +1112,7 @@ gegl_buffer_sample (GeglBuffer       *buffer,
                                       "buffer", buffer,
                                       "format", format,
                                       NULL);
+      buffer->sampler_format = format;
       gegl_sampler_prepare (buffer->sampler);
     }
   gegl_sampler_get (buffer->sampler, x, y, dest);
diff --git a/gegl/buffer/gegl-buffer-private.h b/gegl/buffer/gegl-buffer-private.h
index 4d626fd..33a14e9 100644
--- a/gegl/buffer/gegl-buffer-private.h
+++ b/gegl/buffer/gegl-buffer-private.h
@@ -53,7 +53,7 @@ struct _GeglBuffer
   GeglSampler      *sampler; /* cached sampler for speeding up random
                                 access interpolated fetches from the
                                 buffer */
-  Babl             *sampler_format; /* the format of the cached sampler */
+  const Babl       *sampler_format; /* the format of the cached sampler */
 
   GeglTileStorage  *tile_storage;