new test case added; fix bug (create new assert node when different condition)

theano/gof/opt.py

@@ -634,7 +634,9 @@ class MergeFeature(object):
                         new_inputs.append(cand_i)
                     else:
                         new_inputs.append(
-                            theano.tensor.and_(node_cond, cand_cond))
+                            theano.tensor.opt.assert_op(
+                                node_i.owner.inputs[0],
+                                theano.tensor.and_(node_cond, cand_cond)))
 
                 # node_i is assert, cand_i is not assert
                 else:

theano/gof/tests/test_opt.py

@@ -6,6 +6,9 @@ from theano.gof.opt import *  # noqa
 from theano.gof.fg import FunctionGraph as Env
 from theano.gof.toolbox import *  # noqa
 
+from theano.tensor.opt import Assert
+from theano import tensor as T
+
 
 def as_variable(x):
     if not isinstance(x, Variable):
@@ -360,6 +363,41 @@ class TestMergeOptimizer:
         strg = str(g)
         assert strg == '[Op1(y, y)]' or strg == '[Op1(z, z)]'
 
+    def test_assert_merge(self):
+        x1 = T.matrix('x1')
+        x2 = T.matrix('x2')
+        y1 = T.opt.assert_op(x1, (x1 < 0).all()) +\
+            T.opt.assert_op(x2, (x1 < 0).all())
+        y2 = T.opt.assert_op(x1, (x2 > 0).all()) + x2
+        g = Env([x1, x2], [y1, y2])
+        MergeOptimizer().optimize(g)
+        strg = theano.printing.debugprint(g, file='str')
+        strref = '''
+Elemwise{add,no_inplace} [@A] ''   9
+ |Assert{msg='Theano Assert failed!'} [@B] ''   8
+ | |x1 [@C]
+ | |Elemwise{and_,no_inplace} [@D] ''   7
+ |   |Elemwise{and_,no_inplace} [@E] ''   6
+ |   | |All [@F] ''   3
+ |   | | |Elemwise{lt,no_inplace} [@G] ''   1
+ |   | |   |x1 [@C]
+ |   | |   |DimShuffle{x,x} [@H] ''   0
+ |   | |     |TensorConstant{0} [@I]
+ |   | |All [@J] ''   4
+ |   |   |Elemwise{gt,no_inplace} [@K] ''   2
+ |   |     |x2 [@L]
+ |   |     |DimShuffle{x,x} [@H] ''   0
+ |   |All [@J] ''   4
+ |Assert{msg='Theano Assert failed!'} [@M] ''   5
+   |x2 [@L]
+   |All [@F] ''   3
+Elemwise{add,no_inplace} [@A] ''   9
+'''
+        print(strg)
+        print(strref)
+        assert strg.strip() == strref.strip()
+
+
 
 class TestEquilibrium(object):