sslutil: work around validator crash getting certificate on failed sockets

The previous workaround for correct handling of wrapping of failing connections
might be enough to prevent this from happening, but the check here makes this
function more robust.

mercurial/sslutil.py

@@ -110,6 +110,8 b' class validator(object):'
             self.ui.warn(_("warning: certificate for %s can't be verified "
                            "(Python too old)\n") % host)
             return
+        if not sock.cipher(): # work around http://bugs.python.org/issue13721
+            raise util.Abort(_('%s ssl connection error') % host)
         peercert = sock.getpeercert(True)
         peerfingerprint = util.sha1(peercert).hexdigest()
         nicefingerprint = ":".join([peerfingerprint[x:x + 2]