diff -r 9becd05476b8 -r 131f8cd2c2b4 mercurial/configitems.py
--- a/mercurial/configitems.py	Fri Jun 30 03:45:41 2017 +0200
+++ b/mercurial/configitems.py	Fri Jun 30 03:45:42 2017 +0200
@@ -612,6 +612,9 @@
 coreconfigitem('web', 'deny_read',
     default=list,
 )
+coreconfigitem('web', 'descend',
+    default=True,
+)
 coreconfigitem('worker', 'backgroundclose',
     default=dynamicdefault,
 )