Register most stuff only once

flask/app.py

@@ -583,6 +583,7 @@ class Flask(_PackageBoundObject):
 
         .. versionadded:: 0.7
         """
+        first_registration = False
         if blueprint.name in self.blueprints:
             assert self.blueprints[blueprint.name] is blueprint, \
                 'A blueprint\'s name collision ocurred between %r and ' \
@@ -590,7 +591,8 @@ class Flask(_PackageBoundObject):
                 (blueprint, self.blueprints[blueprint.name], blueprint.name)
         else:
             self.blueprints[blueprint.name] = blueprint
-        blueprint.register(self, options)
+            first_registration = True
+        blueprint.register(self, options, first_registration)
 
     def add_url_rule(self, rule, endpoint=None, view_func=None, **options):
         """Connects a URL rule.  Works exactly like the :meth:`route`