diff -r ec45d7a6d799 -r 16d73491416b mercurial/configitems.py
--- a/mercurial/configitems.py	Wed Oct 11 05:01:55 2017 +0200
+++ b/mercurial/configitems.py	Sun Oct 08 21:29:24 2017 +0200
@@ -662,6 +662,10 @@
 coreconfigitem('sparse', 'missingwarning',
     default=True,
 )
+coreconfigitem('templates', '.*',
+    default=None,
+    generic=True,
+)
 coreconfigitem('trusted', 'groups',
     default=list,
 )