[gimp] app: gimp:threshold-alpha propagate babl space

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 11dd90eb8993233c3917bcf0c4d4580e40e1e306
Author: Øyvind Kolås <pippin gimp org>
Date:   Fri Jul 6 15:09:18 2018 +0200

    app: gimp:threshold-alpha propagate babl space

 app/operations/gimpoperationthresholdalpha.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/app/operations/gimpoperationthresholdalpha.c b/app/operations/gimpoperationthresholdalpha.c
index d79bc68c92..0c9777a1ab 100644
--- a/app/operations/gimpoperationthresholdalpha.c
+++ b/app/operations/gimpoperationthresholdalpha.c
@@ -142,8 +142,9 @@ gimp_operation_threshold_alpha_set_property (GObject      *object,
 static void
 gimp_operation_threshold_alpha_prepare (GeglOperation *operation)
 {
-  gegl_operation_set_format (operation, "input",  babl_format ("RGBA float"));
-  gegl_operation_set_format (operation, "output", babl_format ("RGBA float"));
+  const Babl *space = gegl_operation_get_source_space (operation, "input");
+  gegl_operation_set_format (operation, "input",  babl_format_with_space ("RGBA float", space));
+  gegl_operation_set_format (operation, "output", babl_format_with_space ("RGBA float", space));
 }
 
 static gboolean