ssh: skip noise generated by remote shell

we send a dummy command with known output to get in sync

mercurial/sshrepo.py

@@ -36,6 +36,16 b' class sshrepository(remoterepository):'
         ui.note('running %s\n' % cmd)
         self.pipeo, self.pipei, self.pipee = os.popen3(cmd, 'b')
 
+        # skip any noise generated by remote shell
+        r = self.do_cmd("between", pairs=("%s-%s" % ("0"*40, "0"*40)))
+        l1 = ""
+        while 1:
+            l2 = r.readline()
+            self.readerr()
+            if l1 == "1\n" and l2 == "\n":
+                break
+            l1 = l2
+
     def readerr(self):
         while 1:
             size = os.fstat(self.pipee.fileno())[stat.ST_SIZE]