[PATCH 1 of 2 phases] phases: add a mutable boolean property on context

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at ens-lyon.org>
# Date 1324333898 -3600
# Node ID 53c82dfce4718c3441f249ca96985ba0ac962faf
# Parent  21eb048edc19a9b78ae262d222c0de1f3ad6c4d2
phases: add a mutable boolean property on context

diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -124,6 +124,8 @@
             # outdated cache
             del self._repo._phaserev
         return self._repo._phaserev[self._rev]
+    def mutable(self):
+        return self._repo._phaserev[self._rev] > 0
     def hidden(self):
         return self._rev in self._repo.changelog.hiddenrevs