Re: how does "clone --filter=sparse:path" work?

[Jeff King <peff@peff.net>]

On Thu, Nov 08, 2018 at 01:57:52PM -0500, Jeff Hostetler wrote:

> > Should we simply be disallowing sparse:path filters over upload-pack?
> 
> The option to allow an absolute path over the wire probably needs more
> thought as you suggest.
> 
> Having it in the traverse code was useful for local testing in the
> client.
> 
> But mainly I was thinking of a use case on the client of the form:
> 
>     git rev-list
>         --objects
>         --filter=spec:path=.git/sparse-checkout
>         --missing=print
>         <commit>
> 
> and get a list of the blobs that you don't have and would need before
> you could checkout <commit> using the current sparse-checkout definition.
> You could then have a pre-checkout hook that would bulk
> fetch them before starting the actual checkout.  Since that would be
> more efficient than demand-loading blobs individually during the
> checkout.  There's more work to do in this area, but that was the idea.
> 
> But back to your point, yes, I think we should restrict this over the
> wire.

Thanks for your thorough response, and sorry for the slow reply. I had
meant to reply with a patch adding in the restriction, but I haven't
quite gotten to it. :)

It's still on my todo list, but I'm going to be offline for a bit for
vacation, and I didn't want to leave this totally hanging without a
response.

-Peff