Re: [PATCH] fetch: print an error when declining to request an unadvertised object

[Matt McCutchen <matt@mattmccutchen.net>]

On Fri, 2017-02-10 at 10:36 -0800, Junio C Hamano wrote:
> > 
> There is this piece of code near the end of builtin/fetch-pack.c:
> 
> [...]
> 
> that happens before the command shows the list of fetched refs, and
> this code is prepared to inspect what happend to the requests it (in
> response to the user request) made to the underlying fetch
> machinery, and issue the error message.
> If you change your command line to "git fetch-pack REMOTE SHA1", you
> do see an error from the above.

Yes, "error: no such remote ref NNNN", which at least makes clear that
the operation didn't work, though it would be nice to give a more
specific error message.

> This all happens in transport.c::fetch_refs_via_pack().
> I think that function is a much better place to error or die than
> filter_refs().

I confirmed that checking the sought refs there works.  However, in
filter_refs, it's easy to give a more specific error message that the
server doesn't allow requests for unadvertised objects, and that code
works for "git fetch-pack" too.  To do the same in fetch_refs_via_pack,
we'd have to duplicate a few lines of code from filter_refs and expose
the allow_unadvertised_object_request variable, or just set a flag on
the "struct ref" in filter_refs and check it in fetch_refs_via_pack.

What do you think?  Do you not care about having a more specific error,
in which case I can copy the code from builtin/fetch-pack.c to
fetch_refs_via_pack?  Or shall I add code to filter_refs to set a flag
and add code to builtin/fetch-pack.c and fetch_refs_via_pack to check
the flag?  Or what?

Matt