Fixed backporting bug (conditional expression not parse correctly in my head)

theano/scalar/basic.py

@@ -733,15 +733,16 @@ class Clip(ScalarOp):
         else:
           return x
 
+        #backport
         #return min if x < min else max if x > max else x
     def c_code(self, node, name, (x, min, max), (z, ), sub):
         return "%(z)s = %(x)s < %(min)s ? %(min)s : %(x)s > %(max)s ? %(max)s : %(x)s;" % locals()
     def grad(self, (x, min, max), (gz, )):
         gx = ((x > min) & (x < max)) * gz
         if x.type in grad_types:
-          return gx
+          return gx, None, None
         else:
-          return None,None,None
+          return None, None, None
 
         #return gx if x.type in grad_types else None, None, None
 clip = Clip(transfer_type(0), name = 'clip')
@@ -753,7 +754,7 @@ class First(BinaryScalarOp):
         return "%(z)s = %(x)s;" % locals()
     def grad(self, (x, y), (gz, )):
         if x.type in grad_types:
-          return gz
+          return gz, None
         else:
           return None,None
         #backport