Re: [PATCH v2] fetch: document and test --refmap=""

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

Jeff King <peff@peff.net> writes:

> On Tue, Jan 21, 2020 at 01:38:12AM +0000, Derrick Stolee via GitGitGadget wrote:
>
>> Update the documentation to clarify how '--refmap=""' works and
>> create tests to guarantee this behavior remains in the future.
>
> Yeah, this looks like a good solution to me.
>
>> This can be accomplished by overriding the configured refspec using
>> '--refmap=' along with a custom refspec:
>> 
>>   git fetch <remote> --refmap= +refs/heads/*:refs/hidden/<remote>/*
>
> This isn't strictly related to your patch, but since the rationale here
> describes the concept of a background job and people might end up using
> it as a reference, do you want to add in --no-tags to help them out?

Also, is the order of the arguments correct?  I would have expected
to see <remote> after all dashed options and before refspecs.

> If it makes you feel better, I only found --refmap because I was the one
> who implemented the original "update based on refspecs" logic, and while
> looking for that commit with "git log --grep=opportunistic" I stumbled
> onto Junio's commit adding --refmap, which referenced mine. Maybe this
> also works as a good case study in why we should write good commit
> messages and refer to related work. :)

;-)

> Anyway, I wasn't at all sure that a blank --refmap= would do what you
> want until I tried it. But it was always intended to work that way. From
> c5558f80c3 (fetch: allow explicit --refmap to override configuration,
> 2014-05-29):
>
>   +static int parse_refmap_arg(const struct option *opt, const char *arg, int unset)
>   +{
>   +       ALLOC_GROW(refmap_array, refmap_nr + 1, refmap_alloc);
>   +
>   +       /*
>   +        * "git fetch --refmap='' origin foo"
>   +        * can be used to tell the command not to store anywhere
>   +        */
>   +       if (*arg)
>   +               refmap_array[refmap_nr++] = arg;
>   +       return 0;
>   +}

Good analysis, and also the answer to my previous question is also
there ;-)