[gimp/gimp-2-10] app: in gimp_gegl_create_flatten_node(), explicitly set color node format

[Ell <ell src gnome org>]

commit 3f1e91fa0bb000c2e68a64bd8ce4db8af2efc334
Author: Ell <ell_se yahoo com>
Date:   Mon Feb 25 11:10:17 2019 -0500

    app: in gimp_gegl_create_flatten_node(), explicitly set color node format
    
    In gimp_gegl_create_flatten_node(), explicitly set the output
    format of the background gegl:color node according to the composite
    space, so that no conversion is required during compositing.
    
    (cherry picked from commit ebf2c2fef13edf77524b906e39b2fc1d1aa686a6)

 app/gegl/gimp-gegl-nodes.c | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/app/gegl/gimp-gegl-nodes.c b/app/gegl/gimp-gegl-nodes.c
index 3236f3d5e9..b12f3a1ca5 100644
--- a/app/gegl/gimp-gegl-nodes.c
+++ b/app/gegl/gimp-gegl-nodes.c
@@ -55,6 +55,11 @@ gimp_gegl_create_flatten_node (const GimpRGB       *background,
   color = gegl_node_new_child (node,
                                "operation", "gegl:color",
                                "value",     c,
+                               "format",    gimp_layer_mode_get_format (
+                                              GIMP_LAYER_MODE_NORMAL,
+                                              composite_space,
+                                              GIMP_LAYER_COLOR_SPACE_AUTO,
+                                              NULL),
                                NULL);
   g_object_unref (c);