[gegl] operation-context: Be forgiving and upfront when listing prerequisites

[Debarshi Ray <debarshir src gnome org>]

commit 55d87996e2af5349567f7920670379ba22a4da6f
Author: Debarshi Ray <debarshir gnome org>
Date:   Fri Dec 21 00:05:02 2018 +0100

    operation-context: Be forgiving and upfront when listing prerequisites

 gegl/operation/gegl-operation-context.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/gegl/operation/gegl-operation-context.c b/gegl/operation/gegl-operation-context.c
index 59ba46992..cff0d91f6 100644
--- a/gegl/operation/gegl-operation-context.c
+++ b/gegl/operation/gegl-operation-context.c
@@ -313,6 +313,8 @@ gegl_operation_context_get_target (GeglOperationContext *context,
   g_return_val_if_fail (GEGL_IS_OPERATION_CONTEXT (context), NULL);
 #endif
 
+  g_return_val_if_fail (g_strcmp0 (padname, "output") == 0, NULL);
+
   if (linear_buffers == -1)
     linear_buffers = g_getenv ("GEGL_LINEAR_BUFFERS")?1:0;
 
@@ -327,7 +329,6 @@ gegl_operation_context_get_target (GeglOperationContext *context,
       format = gegl_babl_rgba_linear_float ();
     }
   g_assert (format != NULL);
-  g_assert (!strcmp (padname, "output"));
 
   result = &context->result_rect;