Add test to make sure dots are pushed out.

theano/scan_module/tests/test_scan.py

@@ -3120,6 +3120,25 @@ class T_Scan(unittest.TestCase):
         utt.assert_allclose(vnh0, tnh0, atol=1e-6)
         utt.assert_allclose(vnW, tnW, atol=1e-6)
 
+    def test_pushout_dot(self):
+        W = tensor.matrix('W')
+        h = tensor.matrix('h')
+
+        o, _ = theano.scan(lambda hi, him1, W: (hi, tensor.dot(hi+him1, W)),
+                           outputs_info=[tensor.zeros([h.shape[1]]), None],
+                           sequences=[h],
+                           non_sequences=[W])
+
+        f = theano.function([W, h], o, mode=mode_with_opt)
+
+        scan_nodes = [x for x in f.maker.fgraph.toposort()
+                     if isinstance(x.op,
+                                   theano.scan_module.scan_op.Scan)]
+        assert len(scan_nodes) == 1
+        scan_op = scan_nodes[0].op
+        assert not any(isinstance(n.op, tensor.Dot) for n in
+                       scan_op.fn.maker.fgraph.apply_nodes)
+
     def test_pushout_all(self):
         W1 = tensor.matrix('W1')
         W2 = tensor.matrix('W2')