make fill_sink be applied on all its clients

theano/tensor/opt.py

@@ -3596,18 +3596,18 @@ def local_fill_sink(node):
 
     # The newly created node c doesn't has 'clients',
     # so this iteration is took place with node.outputs[0]
+    replacements = {node.outputs[0]: c}
     for client, _ in node.outputs[0].clients:
         if (hasattr(client, 'op') and
                 isinstance(client.op, T.Elemwise) and
                 not client.op == T.fill):
-            # node_sub_c = client.op([v for v in client.inputs if v is not c])
             # import ipdb; ipdb.set_trace()
             r = local_fill_sink.transform(client)
-            if isinstance(r, list):
-                return {client.outputs[0]: r[0]}
-            elif isinstance(r, dict):
-                return r
-    return [c]
+            if r is False:
+                continue
+            replacements.pop(node.outputs[0], None)
+            replacements.update(r)
+    return replacements
 
 register_canonicalize(local_fill_sink)