Johannes Schindelin [off-list ref] writes:
FWIW I dug out the original submission:
http://thread.gmane.org/gmane.comp.version-control.git/151297/focus=151435
It seems that there was no discussion about the commit-msg. Which makes me
wonder why nobody thought of this.
I actually think it was a mistaken argument.
We could have devised a mechanism to prevent "git commit" that
concludes a conflicted "git merge" from calling the hook to resolve
the inconsistency, and the solution would have been equally valid.
I'd rather not make things worse by repeating that same mistake. If
we were to change anything, we should be adding prepare-merge-msg as
you suggested earlier and weaning people off of the current
behaviour that was added by mistake.
Thanks.