[gegl] gegl-chain: only link input pad when it exists

[Øyvind Kolås <ok src gnome org>]

commit f929f392da739f7c39ca8f1d6dc46a411a983614
Author: Øyvind Kolås <pippin gimp org>
Date:   Tue Jun 20 01:22:23 2017 +0200

    gegl-chain: only link input pad when it exists

 gegl/gegl-serialize.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gegl/gegl-serialize.c b/gegl/gegl-serialize.c
index bae2868..a2a3ceb 100644
--- a/gegl/gegl-serialize.c
+++ b/gegl/gegl-serialize.c
@@ -540,7 +540,7 @@ gegl_create_chain_argv (char      **ops,
                                                proxy), "operation",
                                              level_op[level], NULL);
 
-                  if (iter[level])
+                  if (iter[level] && gegl_node_has_pad (new, "input"))
                     gegl_node_link_many (iter[level], new, proxy, NULL);
                   else
                     gegl_node_link_many (new, proxy, NULL);