Re: [PATCH] Documentation/git-blame.txt: --follow is a NO-OP

On Sep 19, 2012, at 12:42 PM, Jeff King [off-list ref] wrote:

quoted

So I am in general OK with it, but if we are to go that route, we
should make sure that the documentation makes it clear that blame
follows whole-file renames without any special instruction before
doing so.  Otherwise, it again will send the same wrong message to
people who try to use the "--follow" from their experience with
"log", no?

I guess it depends on your perspective. I can see the argument that
blame is already doing what --follow would ask for, and thus it is a
no-op. I think of it more as --follow is nonsensical for blame. But I
do not think either is wrong per se, and there is no reason not to help
people who come to git thinking the former. So yes, I think
documentation in either case is probably a good thing.

I am a little lukewarm on my patch if only because of the precedent it
sets.  There are a trillion options that revision.c parses that are not
necessarily meaningful or implemented for sub-commands that piggy-back
on its option parser. I'm not sure we want to get into manually
detecting and disallowing each one in every caller.

I tend to agree with your final sentiment there. But the point that
users may not realize that blame already follows is also valid. Perhaps
we should catch --follow, as in your patch, but instead of saying that
it's an unknown argument, just print out a helpful message saying blame
already follows renames (and then continue with the blame anyway, so
as to not set a precedent to abort on unknown-but-currently-accepted
flags).

-Kevin