Re: [PATCH] Deprecate support for .git/info/grafts

From: Stefan Beller <sbeller@google.com>
Date: Apr 13, 2018, 18:22 UTC
Message-ID: <CAGZ79kbEec_U5wL_aOS5O_3+ZOshGwARALpjz801h-fRx-zotA@mail.gmail.com>
In-Reply-To: <0f0942043678fe76f8d654306482ee26fac643f0.1523617836.git.johannes.schindelin@gmx.de>

Hi Johannes,

On Fri, Apr 13, 2018 at 4:11 AM, Johannes Schindelin <johannes.schindelin@gmx.de> wrote:

> The grafts feature was a convenient way to "stich together" ancient
> history to the fresh start of linux.git.

Did you mean: stitch?

Show 15 quoted lines

> Its implementation is, however, not up to Git's standards, as there are
> too many ways where it can lead to surprising and unwelcome behavior.
>
> For example, when pushing from a repository with active grafts, it is
> possible to miss commits that have been "grafted out", resulting in a
> broken state on the other side.
>
> Also, the grafts feature is limited to "rewriting" commits' list of
> parents, it cannot replace anything else.
>
> The much younger feature implemented as `git replace` set out to remedy
> those limitations and dangerous bugs.
>
> Seeing as `git replace` is pretty mature by now, it is time to deprecate
> support for the graft file, and to retire it eventually.

It seems that the maturity needed for this commit was reached in 4228e8bc98 (replace: add --graft option, 2014-07-19)

Reviewed-by: Stefan Beller <sbeller@google.com>

> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---

Show 9 quoted lines

>                 return -1;
> +       if (advice_graft_file_deprecated)
> +               advise(_("Support for <GIT_DIR>/info/grafts is deprecated\n"
> +                        "and will be removed in a future Git version.\n"
> +                        "\n"
> +                        "Please use \"git replace --graft [...]\" instead.\n"
> +                        "\n"
> +                        "Turn this message off by running\n"
> +                        "\"git config advice.graftFileDeprecated false\""));

So the user would have to run:

  for line in <GIT_DIR>/info/grafts:
      git replace --graft $line
      # The order in the grafts file is the same as the arguments,
      # but we'd have to pass each as its own argument
  rm <GIT_DIR>/info/grafts

I wonder if we want to offer a migration tool or just leave it at this hint.

Thanks, Stefan