Test for mismatched types in then/else branches.

theano/sandbox/cuda/tests/test_var.py

@@ -2,6 +2,10 @@ import numpy
 from nose.plugins.skip import SkipTest
 
 import theano
+from theano import tensor
+
+from theano.ifelse import ifelse
+from theano.tensor import TensorType
 from theano.sandbox.cuda.var import float32_shared_constructor as f32sc
 from theano.sandbox.cuda import CudaNdarrayType, cuda_available
 
@@ -61,9 +65,32 @@ def test_updates2():
     output_var = f32sc(name="output",
             value=numpy.zeros((10,10), 'float32'))
 
-    x = theano.tensor.fmatrix('x')
+    x = tensor.fmatrix('x')
     output_updates = {output_var:x**2}
     output_givens = {x:data}
     output_func = theano.function(inputs=[], outputs=[],
             updates=output_updates, givens=output_givens)
     output_func()
+
+def test_ifelse():
+    data = numpy.float32([1,2,3,4])
+    x = f32sc(data)
+    y = x + 1
+    cond = theano.tensor.iscalar('cond')
+
+    assert isinstance(x.type, CudaNdarrayType)
+    assert isinstance(y.type, TensorType)
+
+    out1 = ifelse(cond, x, x+1)
+    out2 = ifelse(cond, x+1, x)
+
+    assert isinstance(out1.type, TensorType)
+    assert isinstance(out2.type, TensorType)
+
+    f = theano.function([cond], out1)
+    g = theano.function([cond], out2)
+
+    assert numpy.all(f(0) == data+1)
+    assert numpy.all(f(1) == data)
+    assert numpy.all(g(0) == data)
+    assert numpy.all(g(1) == data+1)