[gegl] svg-luminancetoalpha: propagate space

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

commit ce43089bdd5963baf9d233dc0a6c81e88eff793a
Author: Øyvind Kolås <pippin gimp org>
Date:   Thu Jul 5 23:00:03 2018 +0200

    svg-luminancetoalpha: propagate space

 operations/common/svg-luminancetoalpha.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/operations/common/svg-luminancetoalpha.c b/operations/common/svg-luminancetoalpha.c
index 96ff64c8d..bf3b0059d 100644
--- a/operations/common/svg-luminancetoalpha.c
+++ b/operations/common/svg-luminancetoalpha.c
@@ -36,7 +36,8 @@
 
 static void prepare (GeglOperation *operation)
 {
-  const Babl *format = babl_format ("RaGaBaA float");
+  const Babl *space = gegl_operation_get_source_space (operation, "input");
+  const Babl *format = babl_format_with_space ("RaGaBaA float", space);
 
   gegl_operation_set_format (operation, "input", format);
   gegl_operation_set_format (operation, "output", format);