Replace mutable default arguments

This fixes IRC permission checks. Previously all users who joined the
channel after the bot stored their modes in the same set().

Can be detected with pylint W0102.

1 files changed, 2 insertions, 2 deletions

diff --git a/crocoite/controller.py b/crocoite/controller.py
index eb8908c..788a131 100644
--- a/crocoite/controller.py
+++ b/crocoite/controller.py
@@ -108,13 +108,13 @@ class SinglePageController:
 
     def __init__ (self, url, logger, \
             service, behavior=cbehavior.available, \
-            settings=defaultSettings, handler=[]):
+            settings=defaultSettings, handler=None):
         self.url = url
         self.service = service
         self.behavior = behavior
         self.settings = settings
         self.logger = logger.bind (context=type (self).__name__, url=url)
-        self.handler = handler
+        self.handler = handler or []
 
     def processItem (self, item):
         for h in self.handler: