httpconnection: correctly handle redirects from http to https

Previously the connection cache for keepalives didn't keep track of
ssl. This meant that when we connected to an https server after that
same server via http, both on the default port, we'd incorrectly reuse
the non-https connection as the default port meant the connection
cache key was the same.

mercurial/httpconnection.py

@@ -132,7 +132,7 b' class http2handler(urllib2.HTTPHandler, '
         self._connections = {}
 
     # shamelessly borrowed from urllib2.AbstractHTTPHandler
-    def do_open(self, http_class, req):
+    def do_open(self, http_class, req, use_ssl):
         """Return an addinfourl object for the request, using http_class.
 
         http_class must implement the HTTPConnection API from httplib.
@@ -173,7 +173,8 b' class http2handler(urllib2.HTTPHandler, '
         if not host:
             raise urllib2.URLError('no host given')
 
-        allconns = self._connections.get((host, proxy), [])
+        connkey = use_ssl, host, proxy
+        allconns = self._connections.get(connkey, [])
         conns = [c for c in allconns if not c.busy()]
         if conns:
             h = conns[0]
@@ -185,7 +186,7 b' class http2handler(urllib2.HTTPHandler, '
             if req.timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
                 timeout = req.timeout
             h = http_class(host, timeout=timeout, proxy_hostport=proxy)
-            self._connections.setdefault((host, proxy), []).append(h)
+            self._connections.setdefault(connkey, []).append(h)
 
         headers = dict(req.headers)
         headers.update(req.unredirected_hdrs)
@@ -217,7 +218,7 b' class http2handler(urllib2.HTTPHandler, '
     def http_open(self, req):
         if req.get_full_url().startswith('https'):
             return self.https_open(req)
-        return self.do_open(HTTPConnection, req)
+        return self.do_open(HTTPConnection, req, False)
 
     def https_open(self, req):
         res = readauthforuri(self.ui, req.get_full_url())
@@ -227,7 +228,7 b' class http2handler(urllib2.HTTPHandler, '
             self.ui.debug("using auth.%s.* for authentication\n" % group)
         else:
             self.auth = None
-        return self.do_open(self._makesslconnection, req)
+        return self.do_open(self._makesslconnection, req, True)
 
     def _makesslconnection(self, host, port=443, *args, **kwargs):
         keyfile = None