Re: [PATCH 2/5] fast-import: support 'encoding' commit header

[Eric Sunshine <sunshine@sunshineco.com>]

On Thu, Apr 25, 2019 at 11:51 AM Elijah Newren <newren@gmail.com> wrote:
> Since git supports commit messages with an encoding other than utf-8,
> allow fast-import to import such commits.  This may be useful for folks
> who do not want to reencode commit messages from an external system, and
> may also be useful to achieve reversible history rewrites (e.g. sha1sum
> <-> sha256sum transitions or subtree work) with git repositories that
> have used specialized encodings in their commit history.
>
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
> diff --git a/fast-import.c b/fast-import.c
> @@ -2607,6 +2608,9 @@ static void parse_new_commit(const char *arg)
>         if (!committer)
>                 die("Expected committer but didn't get one");
> +       if (skip_prefix(command_buf.buf, "encoding ", &encoding)) {
> +               read_next_command();
> +       }

Style nit: unnecessary braces

> @@ -2670,9 +2674,13 @@ static void parse_new_commit(const char *arg)
>         strbuf_addf(&new_data,
>                 "author %s\n"
> -               "committer %s\n"
> -               "\n",
> +               "committer %s\n",
>                 author ? author : committer, committer);
> +       if (encoding)
> +               strbuf_addf(&new_data,
> +                       "encoding %s\n",
> +                       encoding);
> +       strbuf_addf(&new_data, "\n");

Alternately:

    strbuf_addch(&new_data, '\n');

> diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
> @@ -3299,4 +3299,24 @@ test_expect_success !MINGW 'W: get-mark & empty orphan commit with erroneous thi
> +test_expect_success 'X: handling encoding' '
> +       test_tick &&
> +       [...]
> +       git cat-file -p encoding | grep $(printf "\360") &&
> +       git log -1 --format=%B encoding | grep $(printf "\317\200")

This script is already full of instances of Git commands upstream of
pipes, so this usage is consistent (despite recent work to eliminate
such situations). Okay.