Re: [PATCH] remote: introduce config to set prefetch refs

[Shubham Kanodia <shubham.kanodia10@gmail.com>]

On Sun, Sep 15, 2024 at 1:41 AM Junio C Hamano <gitster@pobox.com> wrote:
>
> Shubham Kanodia <shubham.kanodia10@gmail.com> writes:
>
> > If we're trying to determine if a pattern
> > (remote.<remote>.prefetchref) is a subset of another or not
> > (remote.<remote>.fetch) (to not accidentally expand the scope beyond
> > `fetch`),
> > we'd need a function that does that pattern-to-pattern. Are you aware
> > of any existing functions that do so?
>
> There is no such computation for this application.  Such a
> computation might become needed if you wanted to complain that the
> user gave .prefetchref pattern that would never match what .fetch
> patterns would allow to pass.  But there is no such need.
>
> You will first get the advertised refs from the remote.
>
> Existing logic filteres them down to what matches configured
> remote.$name.fetch variable.  filter_prefetch_refspec() may further
> reduces the result by removing those whose .src side begins with
> "refs/tags/".
>
> Now you only look at what survived the above existing filtering, and
> further narrow it down by picking only ones that match the prefetch
> condition.  If the refspec that survived the filtering by the fetch
> refspec (and existing logic in filter_prefetch_refspec()) does not
> satisfy the prefetch condition, it won't be prefetched.
>
> Since you are using .prefetch ONLY TO narrow the result down, by
> definition, you are not adding anything what .fetch configuration
> would not have fetched.
>
>

Ah I see — I assumed you expected all filtering for `prefetch`
(existing & new) to happen inside `filter_prefetch_refspec`.
But that threw me off, because `filter_prefetch_refspec` doesn't deal
with advertised refs from remote, and only patterns.

Let me know if the diff in the following mail is closer to what you
were expecting?