Re: [PATCH] Re: Make 'git show' more useful

[Linus Torvalds <torvalds@linux-foundation.org>]

On Tue, 14 Jul 2009, Paolo Bonzini wrote:
> 
> So, what about squashing this with Linus's patch?  (This is meant to be
> squashed, which is why this text is not in a cover letter).

I wouldn't squash it.

That said, in the original commit that introduced "no_walk" (ba1d4505), I 
said

    I was going to add "--no-walk" as a real argument flag to git-rev-list
    too, but I'm not sure anybody actually needs it. Although it might be
    useful for porcelain, so I left the door open.

and I never actually did it. That was Apr 15, 2006.

The actual "--no-walk" flag was then added over a year later by Dsco, in 
commit 8e64006eee ("Teach revision machinery about --no-walk").

Doing a "git log -p -S--no-walk", I have to admit that I don't find a 
single actual _use_ of --no-walk. And it obviously wasn't even exported 
until a year after it was internally implemented.

So I have to agree with the fact that "--no-walk" and "--do-walk" seem to 
be pretty worthless as command line switches.  Removing them might be a 
good thing.

However, doing some googling, I do actually find examples of it on the 
web. And some of them even appear valid:

	second_parent=$(git rev-list --no-walk --parents $newrev | sed 's/ /\n/g' | grep -v $newrev | tail --lines=1)

because you can't use "git rev-parse" with --parents (of course, I'm not 
at all clear on why it doesn't do

	second_parent=$(git rev-parse "$newrev"^2)

but that's really immaterial - the point is that "git rev-parse" is _not_ 
a replacement for "git rev-list --no-walk").

So I dunno. I think we might as well leave --no-walk and --do-walk around, 
even though they are of dubious value. They do mirror the internal 
revision walking logic very directly. 

			Linus