diff --git a/hgext/mq.py b/hgext/mq.py
--- a/hgext/mq.py
+++ b/hgext/mq.py
@@ -2043,13 +2043,10 @@ def reposetup(ui, repo):
 
             return tagscache
 
-        def branchtags(self):
-            if self.branchcache != None:
-                return self.branchcache
-
+        def _branchtags(self):
             q = self.mq
             if not q.applied:
-                return super(mqrepo, self).branchtags()
+                return super(mqrepo, self)._branchtags()
 
             self.branchcache = {} # avoid recursion in changectx
             cl = self.changelog
@@ -2069,8 +2066,7 @@ def reposetup(ui, repo):
             # update the cache up to the tip
             self._updatebranchcache(partial, start, cl.count())
 
-            self.branchcache = partial
-            return self.branchcache
+            return partial
 
     if repo.local():
         repo.__class__ = mqrepo
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -312,12 +312,7 @@ class localrepository(repo.repository):
                 self.nodetagscache.setdefault(n, []).append(t)
         return self.nodetagscache.get(node, [])
 
-    def branchtags(self):
-        if self.branchcache != None:
-            return self.branchcache
-
-        self.branchcache = {} # avoid recursion in changectx
-
+    def _branchtags(self):
         partial, last, lrev = self._readbranchcache()
 
         tiprev = self.changelog.count() - 1
@@ -325,6 +320,15 @@ class localrepository(repo.repository):
             self._updatebranchcache(partial, lrev+1, tiprev+1)
             self._writebranchcache(partial, self.changelog.tip(), tiprev)
 
+        return partial
+
+    def branchtags(self):
+        if self.branchcache is not None:
+            return self.branchcache
+
+        self.branchcache = {} # avoid recursion in changectx
+        partial = self._branchtags()
+
         # the branch cache is stored on disk as UTF-8, but in the local
         # charset internally
         for k, v in partial.items():