test that you can have only some outputs inplace

theano/scan_module/tests/test_scan.py

@@ -887,6 +887,34 @@ class T_Scan(unittest.TestCase):
         #assert not numpy.allclose( theano_x0 , vu2[1:4])
         #assert numpy.allclose( theano_x1 , vu1[0:3])
 
+    def test_inplace3(self):
+        rng = numpy.random.RandomState(utt.fetch_seed())
+
+        vx0 = asarrayX(rng.uniform())
+        vx1 = asarrayX(rng.uniform())
+        x0 = theano.shared(vx0)
+        x1 = theano.shared(vx1)
+        outputs, updates = theano.scan(lambda x,y: (x + asarrayX(1),
+                                                    y + asarrayX(1)),
+                                       [],
+                                       [x0,x1],
+                                       n_steps = 3)
+        x0 = asarrayX(numpy.zeros((3,)))
+        x0[0] = vx0
+        x0 = theano.tensor.constant(x0)
+        to_replace = outputs[0].owner.inputs[0].owner.inputs[1]
+        outputs = theano.clone(outputs,
+                               replace={to_replace: x0})
+        mode = theano.compile.mode.get_mode(None).including('inplace')
+        f9 = theano.function([],
+                             outputs,
+                             updates=updates,
+                             mode=mode)
+        scan_node = [x for x in f9.maker.env.toposort()
+                     if isinstance(x.op, theano.scan_module.scan_op.Scan)]
+        assert 0 not in scan_node[0].op.destroy_map.keys()
+        assert 1 in scan_node[0].op.destroy_map.keys()
+
     # Shared variable with updates
     def test_shared_arguments_with_updates(self):
         rng = numpy.random.RandomState(utt.fetch_seed())