cfg.url_prefix_action_check = True to strictly check whether action URLs look like we generate them url_prefix_action was introduced to be able to use robots.txt against bots doing unwanted requests for all sorts of actions, just because they found a link to them in the menu_bar (or somewhere else). Problem: even if url_prefix_action was in use (e.g. == 'action'), we still accepted URls without that prefix (e.g. cached by some bot or search engine from earlier times or external links). Answering those requests can take a lot of CPU time and we can't get rid of them without doing the check that was implemented with this changeset.

--- a/MoinMoin/config/multiconfig.py	Sat Apr 06 23:26:08 2013 +0200
+++ b/MoinMoin/config/multiconfig.py	Sun Apr 07 00:59:26 2013 +0200
@@ -1032,6 +1032,8 @@
 
     ('url_prefix_action', None,
      "Use 'action' to enable action URL generation to be compatible with robots.txt. It will generate .../action/info/PageName?action=info then. Recommended for internet wikis."),
+    ('url_prefix_action_check', False,
+     "Do a strict check whether the URL pathes for actions look like we generate them (otherwise do a 404 response)."),
 
     ('notification_bot_uri', None, "URI of the Jabber notification bot."),