mercurial/httprepo.py

--- a/mercurial/httprepo.py	Fri Jul 29 12:46:45 2011 -0500
+++ b/mercurial/httprepo.py	Wed Jul 27 18:35:35 2011 -0500
@@ -78,6 +78,7 @@
 
         if data and self.ui.configbool('ui', 'usehttp2', False):
             headers['Expect'] = '100-Continue'
+            headers['X-HgHttp2'] = '1'
 
         self.ui.debug("sending %s command\n" % cmd)
         q = [('cmd', cmd)]