--- a/mercurial/help.py	Wed Jun 12 17:22:37 2019 +0100
+++ b/mercurial/help.py	Thu Jun 13 23:28:31 2019 +0300
@@ -320,6 +320,8 @@
      loaddoc('config', subdir='internals')),
     (['extensions', 'extension'], _('Extension API'),
      loaddoc('extensions', subdir='internals')),
+    (['mergestate'], _('Mergestate'),
+     loaddoc('mergestate', subdir='internals')),
     (['requirements'], _('Repository Requirements'),
      loaddoc('requirements', subdir='internals')),
     (['revlogs'], _('Revision Logs'),