# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@ens-lyon.org>
# Date 2013-01-02 00:40:06
# Node ID c0c943ef4e5530c73c9c2302b552e4ce3cb4cd93
# Parent  f5842787a958b8af558bd8aa148f13be6df41992

clfilter: use empty frozenset intead of empty tuple

This will allows set operation needed for cache collaboration.

diff --git a/mercurial/changelog.py b/mercurial/changelog.py
--- a/mercurial/changelog.py
+++ b/mercurial/changelog.py
@@ -124,7 +124,7 @@ class changelog(revlog.revlog):
         self._realopener = opener
         self._delayed = False
         self._divert = False
-        self.filteredrevs = ()
+        self.filteredrevs = frozenset()
 
     def tip(self):
         """filtered version of revlog.tip"""
diff --git a/mercurial/repoview.py b/mercurial/repoview.py
--- a/mercurial/repoview.py
+++ b/mercurial/repoview.py
@@ -17,7 +17,7 @@ def computeunserved(repo):
     # fast path in simple case to avoid impact of non optimised code
     if phases.hassecret(repo) or repo.obsstore:
         return frozenset(repo.revs('hidden() + secret()'))
-    return ()
+    return frozenset()
 
 # function to compute filtered set
 filtertable = {'unserved': computeunserved}