In https://www.hostedredmine.com/issues/809590#note-7 bard says:
"However, I was missing a way to prevent promotions when the defending unit has defense 0 (or no way to damage the attacker)."
I think that natural way to do this is to introduce new "only_real_fight_makes_veteran" setting alongside the existing "only_killing_makes_veteran".
I like it. Thank you. I'll try to test it.
master version of rulesave.c should add the comment, but does not (comments.c part has been made, the only thing missing is call from rulesave.c)
New version for master, with proper saving of the ruleset comment in rulesave.