Blueprint.app_url_value_preprocessor doesn't work correctly.
diff --git a/flask/blueprints.py b/flask/blueprints.py
index 8bfc610e10..ccdda38d54 100644
--- a/flask/blueprints.py
+++ b/flask/blueprints.py
@@ -292,8 +292,8 @@ def url_defaults(self, f):
     def app_url_value_preprocessor(self, f):
         """Same as :meth:`url_value_preprocessor` but application wide.
         """
-        self.record_once(lambda s: s.app.url_value_preprocessor
-            .setdefault(self.name, []).append(f))
+        self.record_once(lambda s: s.app.url_value_preprocessors
+            .setdefault(None, []).append(f))
         return f
 
     def app_url_defaults(self, f):

The code contains a typo, and additionaly it registers a blueprint-local preprocessor instead of a global one.
