url: return the matched authentication group name from readauthforuri()

Internally, the group name is only used in debug statements, but readauthforuri
can be also used externally to determine which group will be matched for a given
URL.

mercurial/url.py

@@ -88,7 +88,7 b' def readauthforuri(ui, uri):'
     scheme, hostpath = uri.split('://', 1)
     bestlen = 0
     bestauth = None
-    for auth in config.itervalues():
+    for group, auth in config.iteritems():
         prefix = auth.get('prefix')
         if not prefix:
             continue
@@ -100,7 +100,7 b' def readauthforuri(ui, uri):'
         if (prefix == '*' or hostpath.startswith(prefix)) and \
             len(prefix) > bestlen and scheme in schemes:
             bestlen = len(prefix)
-            bestauth = auth
+            bestauth = group, auth
     return bestauth
 
 _safe = ('abcdefghijklmnopqrstuvwxyz'
@@ -155,9 +155,11 b' class passwordmgr(urllib2.HTTPPasswordMg'
             return (user, passwd)
 
         if not user:
-            auth = self.readauthtoken(authuri)
-            if auth:
+            res = readauthforuri(self.ui, authuri)
+            if res:
+                group, auth = res
                 user, passwd = auth.get('username'), auth.get('password')
+                self.ui.debug("using auth.%s.* for authentication\n" % group)
         if not user or not passwd:
             if not self.ui.interactive():
                 raise util.Abort(_('http authorization required'))
@@ -180,9 +182,6 b' class passwordmgr(urllib2.HTTPPasswordMg'
         msg = _('http auth: user %s, password %s\n')
         self.ui.debug(msg % (user, passwd and '*' * len(passwd) or 'not set'))
 
-    def readauthtoken(self, uri):
-        return readauthforuri(self.ui, uri)
-
 class proxyhandler(urllib2.ProxyHandler):
     def __init__(self, ui):
         proxyurl = ui.config("http_proxy", "host") or os.getenv('http_proxy')
@@ -624,7 +623,13 b' if has_https:'
             return keepalive.KeepAliveHandler._start_transaction(self, h, req)
 
         def https_open(self, req):
-            self.auth = self.pwmgr.readauthtoken(req.get_full_url())
+            res = readauthforuri(self.ui, req.get_full_url())
+            if res:
+                group, auth = res
+                self.auth = auth
+                self.ui.debug("using auth.%s.* for authentication\n" % group)
+            else:
+                self.auth = None
             return self.do_open(self._makeconnection, req)
 
         def _makeconnection(self, host, port=None, *args, **kwargs):