keep constant_result when coercing BytesNode

diff --git a/Cython/Compiler/ExprNodes.py b/Cython/Compiler/ExprNodes.py
index 860cda8..a2210c8 100755 (executable)
--- a/Cython/Compiler/ExprNodes.py
+++ b/Cython/Compiler/ExprNodes.py
@@ -1157,7 +1157,8 @@ class BytesNode(ConstNode):
             return CharNode(self.pos, value=self.value,
                             constant_result=ord(self.value))
 
-        node = BytesNode(self.pos, value=self.value)
+        node = BytesNode(self.pos, value=self.value,
+                         constant_result=self.constant_result)
         if dst_type.is_pyobject:
             if dst_type in (py_object_type, Builtin.bytes_type):
                 node.type = Builtin.bytes_type