[gimp] app: disable the preview area in gimp_drawable_merge_filter()

[Michael Natterer <mitch src gnome org>]

commit bda7ddc0fd8244f3b93d250464d0c00692fc6197
Author: Michael Natterer <mitch gimp org>
Date:   Tue Feb 16 21:22:58 2016 +0100

    app: disable the preview area in gimp_drawable_merge_filter()
    
    This call has no effect if there was no preview area in the first place.

 app/core/gimpdrawable-filter.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/app/core/gimpdrawable-filter.c b/app/core/gimpdrawable-filter.c
index 17e39e9..3b68e97 100644
--- a/app/core/gimpdrawable-filter.c
+++ b/app/core/gimpdrawable-filter.c
@@ -124,6 +124,13 @@ gimp_drawable_merge_filter (GimpDrawable *drawable,
 
       if (applicator)
         {
+          /*  disable the preview crop, this will force-process the
+           *  cached result from the preview cache into the result
+           *  cache, involving only the layer and affect nodes
+           */
+          gimp_applicator_set_preview (applicator, FALSE,
+                                       GEGL_RECTANGLE (0, 0, 0, 0));
+
           /*  the apply_buffer will make a copy of the region that is
            *  actually processed in gimp_gegl_apply_cached_operation()
            *  below.