diff -r 70f1a84d0794 -r 44e99811bea7 mercurial/ui.py
--- a/mercurial/ui.py	Thu Jul 04 21:29:28 2019 +0530
+++ b/mercurial/ui.py	Sat Jul 06 19:55:29 2019 -0400
@@ -68,6 +68,8 @@
 update.check = noconflict
 # Show conflicts information in `hg status`
 status.verbose = True
+# Make `hg resolve` with no action (like `-m`) fail instead of re-merging.
+resolve.explicit-re-merge = True
 
 [diff]
 git = 1