Assert right number of arguments in make_node.

theano/ifelse.py

@@ -155,6 +155,10 @@ class IfElse(PureOp):
         return out_shapes
 
     def make_node(self, c, *args):
+        assert len(args) == 2 * self.n_outs, (
+                "Wrong number of arguments to make_node: "
+                "expected %d, got %d" % (2 * self.n_outs, len(args))
+        )
         if not self.gpu:
             # When gpu is true, we are given only cuda ndarrays, and we want
             # to keep them be cuda ndarrays