Re: [PATCH] transport-helper: do not request symbolic refs to remote helpers

[Junio C Hamano <gitster@pobox.com>]

Mike Hommey <mh@glandium.org> writes:

> The patch changes the behavior in all cases, because it didn't feel
> necessary to have a different behavior between the "normal" case and the
> '?' case: it makes sense to request the ref being pointed at than the
> symbolic ref in every case.
>
> Moreover, this makes existing non-git remote-helpers work without
> having to modify them to provide a refspec for HEAD (none of the 5
> mercurial remote-helpers I checked do).

I do not question the latter.  It is not surprising if all of them
share the same limitation that shares the same root in the same
impedance mismatch.

The trouble I had in supporting "makes sense ... in every case" was
that you said that the code as patched would not work for a symref
pointing at another symref.  The original code did not have that
problem with remote helpers that support the 'list' command.

Does the new code avoid regressions for them and if so how?  That is
what was needed in the justification.

For remote helpers that support the 'list' command, asking for a
symref and asking for a ref that the symref points at both work OK
and behave the same, and hopefully that would be true even when the
latter is a symref that points yet another ref, so dereferencing
only one level on our end when making a request, instead of letting
the remote side dereference, is not likely to cause regression.