Compute mappings in __init__ and __setstate__ if needed

theano/scan_module/scan_op.py

@@ -229,6 +229,11 @@ class Scan(PureOp):
             self._cmodule_key = gof.CLinker().cmodule_key_(local_fgraph, [])
             self._hash_inner_graph = hash(self._cmodule_key)
 
+        # Compute mappings between outer inputs, outer outputs, inner
+        # inputs and inner outputs to determine with variables are associated
+        # with the same states.
+        self.var_mappings = self.get_oinp_iinp_iout_oout_mappings()
+
     def validate_inner_graph(self):
         """ Perform some elementary validations on the inner graph to ensure
         that it is coherent.
@@ -303,13 +308,19 @@ class Scan(PureOp):
 
     def __setstate__(self, d):
         self.__dict__.update(d)
-        self.validate_inner_graph()
         if "allow_gc" not in self.__dict__:
             self.allow_gc = True
             self.info['allow_gc'] = True
         if not hasattr(self, 'gpua'):
             self.gpua = False
             self.info['gpua'] = False
+        if not hasattr(self, 'var_mappings'):
+            # Generate the mappings between inner and outer inputs and outputs
+            # if they haven't already been generated.
+            self.var_mappings = self.get_oinp_iinp_iout_oout_mappings()
+
+        # Ensure that the graph associated with the inner function is valid.
+        self.validate_inner_graph()
 
     def make_node(self, *inputs):
         """