basectx: move parents from changectx

mercurial/context.py

@@ -80,6 +80,10 b' class basectx(object):'
     def mutable(self):
         return self.phase() > phases.public
 
+    def parents(self):
+        """return contexts for each parent changeset"""
+        return self._parents
+
 class changectx(basectx):
     """A changecontext object makes access to data related to a particular
     changeset convenient. It represents a read-only context already presnt in
@@ -241,10 +245,6 b' class changectx(basectx):'
     def hidden(self):
         return self._rev in repoview.filterrevs(self._repo, 'visible')
 
-    def parents(self):
-        """return contexts for each parent changeset"""
-        return self._parents
-
     def p1(self):
         return self._parents[0]