--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -66,7 +66,7 @@ class changectx(object):
     def date(self): return self._changeset[2]
     def files(self): return self._changeset[3]
     def description(self): return self._changeset[4]
-    def branch(self): return self._changeset[5].get("branch", "")
+    def branch(self): return self._changeset[5].get("branch")
 
     def parents(self):
         """return contexts for each parent changeset"""
@@ -412,11 +412,7 @@ class workingctx(changectx):
     def deleted(self): return self._status[3]
     def unknown(self): return self._status[4]
     def clean(self): return self._status[5]
-    def branch(self):
-        try:
-            return self._repo.opener("branch").read().strip()
-        except IOError:
-            return ""
+    def branch(self): return self._repo.dirstate.branch()
 
     def parents(self):
         """return contexts for each parent changeset"""