diff -r b935adb4b041 -r 3f0ef8d19413 mercurial/cmdutil.py
--- a/mercurial/cmdutil.py	Fri Aug 10 00:28:07 2018 -0400
+++ b/mercurial/cmdutil.py	Fri Aug 10 09:18:37 2018 +0900
@@ -617,7 +617,7 @@
 
 def _mergemsg():
     # tweakdefaults requires `update` to have a rev hence the `.`
-     return _helpmessage('hg commit', 'hg merge --abort')
+    return _helpmessage('hg commit', 'hg merge --abort')
 
 def _bisectmsg():
     msg = _('To mark the changeset good:    hg bisect --good\n'