[gegl] Disable in-place processing when multi threading is enabled.

[Øyvind Kolås <ok src gnome org>]

commit 7315e30da9089954d92a55c55228adcdd7e409f0
Author: �yvind Kolås <pippin gimp org>
Date:   Sat Nov 21 21:48:25 2009 +0000

    Disable in-place processing when multi threading is enabled.
    
    Perhaps the criteria that accepts passthrough processing can
    be improved for the multiprocessing case?

 gegl/operation/gegl-operation-filter.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/gegl/operation/gegl-operation-filter.c b/gegl/operation/gegl-operation-filter.c
index cf24d50..1ebf8a4 100644
--- a/gegl/operation/gegl-operation-filter.c
+++ b/gegl/operation/gegl-operation-filter.c
@@ -187,7 +187,12 @@ gboolean gegl_can_passthrough (GeglOperation       *operation,
                                GeglBuffer          *input,
                                const GeglRectangle *result)
 {
+#if ENABLE_MT
+  /* pass through processing currently conflicts
+   * with in place processing.
+   */
   return FALSE;
+#endif
   if (!input || 
       GEGL_IS_CACHE (input))
     return FALSE;