[gegl] buffer: permit gegl_buffer_sample with NULL format

[Ãyvind KolÃs <ok src gnome org>]

commit 28a2e849c591c79c86144d8d3f52f3e5d75bf8fe
Author: Ãyvind KolÃs <pippin gimp org>
Date:   Tue Mar 27 01:22:18 2012 +0100

    buffer: permit gegl_buffer_sample with NULL format

 gegl/buffer/gegl-buffer-access.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/gegl/buffer/gegl-buffer-access.c b/gegl/buffer/gegl-buffer-access.c
index 6651159..a033e86 100644
--- a/gegl/buffer/gegl-buffer-access.c
+++ b/gegl/buffer/gegl-buffer-access.c
@@ -1106,6 +1106,9 @@ gegl_buffer_sample (GeglBuffer       *buffer,
 
   desired_type = gegl_sampler_gtype_from_enum (sampler_type);
 
+  if (!format)
+    format = buffer->soft_format;
+
   /* unset the cached sampler if it dosn't match the needs */
   if (buffer->sampler != NULL &&
      (!G_TYPE_CHECK_INSTANCE_TYPE (buffer->sampler, desired_type) ||