clone constants only if they belong to an env ( in pfunc)

theano/compile/pfunc.py

@@ -78,6 +78,9 @@ def rebuild_collect_shared( outputs
         clone_d. Also appends all shared variables met along the way to
         shared inputs, and their default_update (if applicable) to update_d
         and update_expr.
+
+        v can have an env attached to it, case in which we want to clone
+        constants ( to avoid having a constant belonging to two envs)
         '''
         # this co-recurses with clone_a
         assert v is not None
@@ -108,7 +111,8 @@ def rebuild_collect_shared( outputs
                                 , (v, v.type, v_update, v_update.type))
                         update_d[v] = v_update
                         update_expr.append((v, v_update))
-        if not copy_inputs_over or isinstance(v, Constant):
+        if not copy_inputs_over or (isinstance(v, Constant) and
+                                    hasattr(v,'env')):
             ### Cloning shared variables implies copying their underlying
             ### memory buffer ?? No.
             return clone_d.setdefault(v,v.clone())