[BUG new back-end ifelse] Fix gh-5252. Sometimes the ifelse always evaluate to True.

theano/gpuarray/tests/test_opt.py

@@ -249,6 +249,21 @@ class test_gpu_ifelse(test_ifelse.test_ifelse):
     def get_ifelse(self, n):
         return theano.ifelse.IfElse(n, gpu=True, as_view=True)
 
+    def test_lifter_with_inputs_of_graph(self):
+        x = tensor.vector()
+        cond = tensor.iscalar()
+        f = theano.function([x, cond],
+                            theano.ifelse.ifelse(cond, x.mean(), x.sum()),
+                            mode=mode_with_gpu)
+        assert f(numpy.float32([1, 2, 3]), 0) == 6
+
+        x = tensor.vector()
+        cond = tensor.scalar()
+        f = theano.function([x, cond],
+                            theano.ifelse.ifelse(cond, x.mean(), x.sum()),
+                            mode=mode_with_gpu)
+        assert f(numpy.float32([1, 2, 3]), 0) == 6
+
 
 def test_print_op():
     """ Test that print ops don't block gpu optimization"""

theano/ifelse.py

@@ -167,10 +167,10 @@ class IfElse(Op):
             "Wrong number of arguments to make_node: "
             "expected %d, got %d" % (2 * self.n_outs, len(args))
         )
+        c = theano.tensor.as_tensor_variable(c)
         if not self.gpu:
             # When gpu is true, we are given only cuda ndarrays, and we want
             # to keep them be cuda ndarrays
-            c = theano.tensor.as_tensor_variable(c)
             nw_args = []
             for x in args:
                 if isinstance(x, theano.Variable):