--- a/mercurial/localrepo.py	Fri Feb 11 22:24:10 2011 +0800
+++ b/mercurial/localrepo.py	Fri Dec 24 15:23:01 2010 +0100
@@ -283,6 +283,8 @@
         # committed tags are stored in UTF-8
         writetags(fp, names, encoding.fromlocal, prevtags)
 
+        fp.close()
+
         if '.hgtags' not in self.dirstate:
             self[None].add(['.hgtags'])