Make work around work when readonly is True.

theano/gof/link.py

@@ -334,7 +334,11 @@ class Container(object):
             not self.type.is_valid_value(r.storage[0])):
 
             assert not data_was_in_memo
-            r.data = r.storage[0]
+            assert self.type.is_valid_value(self.storage[0])
+            # This should also work for read only container.
+            r.storage[0] = self.type.filter(r.storage[0],
+                                            strict=False,
+                                            allow_downcast=False)
             memo[id(self.storage[0])] = r.storage[0]
         return r
 

theano/gof/tests/test_link.py

@@ -193,7 +193,8 @@ def test_container_deepcopy():
     """
     t = theano.tensor.scalar()
     v = numpy.asarray(0.)
-    c = Container(t, [v])
-    assert isinstance(c.storage[0], numpy.ndarray)
-    d = deepcopy(c)
-    assert isinstance(d.storage[0], numpy.ndarray)
+    for readonly in [True, False]:
+        c = Container(t, [v], readonly=readonly)
+        assert isinstance(c.storage[0], numpy.ndarray)
+        d = deepcopy(c)
+        assert isinstance(d.storage[0], numpy.ndarray)