diff -r 5f9d057ba28c -r 6704696141b8 mercurial/configitems.py
--- a/mercurial/configitems.py	Thu Jan 31 20:11:16 2019 +0300
+++ b/mercurial/configitems.py	Wed Feb 13 18:34:08 2019 -0800
@@ -1081,6 +1081,10 @@
     default=None,
     generic=True,
 )
+coreconfigitem('templateconfig', '.*',
+    default=dynamicdefault,
+    generic=True,
+)
 coreconfigitem('trusted', 'groups',
     default=list,
 )