--- a/mercurial/branchmap.py	Sat Apr 13 20:57:50 2019 +0200
+++ b/mercurial/branchmap.py	Mon May 21 17:28:35 2018 +0200
@@ -40,6 +40,7 @@
 subsettable = {None: 'visible',
                'visible-hidden': 'visible',
                'visible': 'served',
+               'served.hidden': 'served',
                'served': 'immutable',
                'immutable': 'base'}