Jörg Sommer [off-list ref] writes:
... But I doubt someone expects this behaviour
because the manpage says:
The second syntax (<msg> HEAD <remote>) is supported for historical
reasons. Do not use it from the command line or in new scripts. It is
the same as git merge -m <msg> <remote>.
^^^^ ^^
Currently, it's not the same, but someone might expect it.
Yeah, the manpage is loosely written and does not reflect the reality. I
am _VERY_ tempted to apply your change as-is and see if anybody screams.
Because git is designed to be very scriptable, people who want the current
behaviour can still call fmt-merge-msg themselves.