Disabled part of an optimization that give wrong result!

theano/tensor/opt.py

@@ -1629,7 +1629,9 @@ def local_sum_div_dimshuffle(node):
         dimshuffled = None
         if thing_summed.owner and thing_summed.owner.op == T.true_div:
             numerator, denominator = thing_summed.owner.inputs
-            if numerator.owner and isinstance(numerator.owner.op, T.DimShuffle):
+            #This if have bad logic. See its test in tensor/tests/test_opt.py:T_local_sum_dimshuffle
+            #that fail when we enable this if.
+            if False and numerator.owner and isinstance(numerator.owner.op, T.DimShuffle):
                 new_order = numerator.owner.op.new_order
                 #print 'new_order =', new_order
                 # check compatibility

theano/tensor/tests/test_opt.py

@@ -1581,8 +1581,11 @@ class T_local_sum_dimshuffle(unittest.TestCase):
             theano.printing.debugprint(f)
             g = f.maker.env.toposort()
             #print 'g =', g
-            assert g[-1].op == T.true_div
-
+            f([[1,1],[1,1]],[1,1],[[[1,1],[1,1]],[[1,1],[1,1]]])
+            num, denum = s.owner.inputs[0].owner.inputs
+            if denum.owner and isinstance(denum.owner.op, T.DimShuffle):
+                assert g[-1].op == T.true_div
+                
     # TODO:
     # test_local_sum_prod_dimshuffle (a * b * c)
     # test_local_sum_divprod_dimshuffle ((a * b) / (c * d))