diff -r 10f8f20e0137 -r 728ecab6634b mercurial/configitems.py
--- a/mercurial/configitems.py	Wed Oct 11 03:49:21 2017 +0200
+++ b/mercurial/configitems.py	Wed Oct 11 03:49:47 2017 +0200
@@ -374,6 +374,9 @@
 coreconfigitem('logtoprocess', 'commandfinish',
     default=None,
 )
+coreconfigitem('logtoprocess', 'command',
+    default=None,
+)
 coreconfigitem('merge', 'checkunknown',
     default='abort',
 )