Re: should git maintenance prefetch be taught to honor remote.fetch refspec?

[Eric Sunshine <sunshine@sunshineco.com>]

On Fri, Apr 2, 2021 at 4:43 PM Derrick Stolee <stolee@gmail.com> wrote:
> I have a branch available [1], but I'm seeing some failures only
> on FreeBSD [2] and I can't understand why that platform is failing
> this test. The current version (as of this writing) does not do
> the substring replacement technique, and hence it just gives up
> on exact matches. I will try the substring approach as an
> alternative and see where that gets me.
>
> [1] https://github.com/gitgitgadget/git/pull/924
> [2] https://github.com/gitgitgadget/git/pull/924/checks?check_run_id=2256079534

The "+" in patterns such as `+refs/heads/\\*:refs/prefetch...` is what
is throwing it off. FreeBSD `grep` doesn't seem to like it, though
it's not clear why. Escaping it the same way as you escaped "*"
doesn't make it work. Replacing "+" with catchall "." does work, so
that's one way to fix it.

However, all the escaping you need to do in these refspec patterns to
pass them to `grep` is ugly. A much better solution may be to change
the `grep` in test-lib-functions.sh:test_subcommand() to `grep -F` to
force it to match literally. That way, you can drop all the backslash
escaping, including those in front of "[" and "]". A cursory audit of
callers test_subcommand() seems to indicate that none of them pass
regex patterns, so using `-F` is probably safe and a good idea.

By the way, the `coccinelle` check is also "failing", correctly
suggesting that you change:

    strbuf_addf(&replace, ":refs/prefetch/");

to:

    strbuf_addstr(&replace, ":refs/prefetch/");

in `builtin/gc.c`.