Re: [PATCH v4 2/4] submodule: update core.worktree using git-config

[Stefan Beller <sbeller@google.com>]

On Wed, Jul 20, 2016 at 10:24 AM, Nguyễn Thái Ngọc Duy
<pclouds@gmail.com> wrote:
> To access a separate repository, the first step should be read its
> config file to determine if this repository layout is supported or
> not, or if we understand all repo extensions, of it is a linked
> worktree. Only then should know where to update the config file.
>
> Unfortunately, our C code base is not ready for doing all that in the
> same process. The repo detection is not meant to be used for peeking
> in other repository, and config code would read config.worktree that
> is in _current_ $GIT_DIR.
>
> For now, let's spawn a new process and let all that done separately.
>
> PS. submodule-helper also updates core.worktree. But in there, we
> create a new clone, we know what is the initial repository layout, so
> we know we can simply update "config" file without risks.

Right, the submodule--helper update_clone should not be required to convert.

>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
> ---
>  submodule.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/submodule.c b/submodule.c
> index abc2ac2..b912871 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -1128,7 +1128,9 @@ void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir)
>  {
>         struct strbuf file_name = STRBUF_INIT;
>         struct strbuf rel_path = STRBUF_INIT;
> +       struct strbuf path = STRBUF_INIT;
>         const char *real_work_tree = xstrdup(real_path(work_tree));
> +       struct child_process cp = CHILD_PROCESS_INIT;
>
>         /* Update gitfile */
>         strbuf_addf(&file_name, "%s/.git", work_tree);
> @@ -1136,13 +1138,17 @@ void connect_work_tree_and_git_dir(const char *work_tree, const char *git_dir)
>                    relative_path(git_dir, real_work_tree, &rel_path));
>
>         /* Update core.worktree setting */
> -       strbuf_reset(&file_name);
> -       strbuf_addf(&file_name, "%s/config", git_dir);
> -       git_config_set_in_file(file_name.buf, "core.worktree",
> -                              relative_path(real_work_tree, git_dir,
> -                                            &rel_path));
> +       strbuf_addstr(&path, relative_path(real_work_tree, git_dir,
> +                                          &rel_path));
> +       cp.git_cmd = 1;
> +       argv_array_pushl(&cp.args, "-C", work_tree, NULL);
> +       argv_array_pushl(&cp.args, "--work-tree", ".", NULL);
> +       argv_array_pushl(&cp.args, "config", "core.worktree", path.buf, NULL);
> +       if (run_command(&cp) < 0)
> +               die(_("failed to update core.worktree for %s"), git_dir);

Do we need to make this conditional on the extensions.worktreeConfig
variable, though? When I just run

    git config --worktree . foo bar
fatal: Per-worktree configuration requires extensions.worktreeConfig
Please read section CONFIGURATION in `git help worktree` before
enabling it.

which would trigger the failure here?

>
>         strbuf_release(&file_name);
> +       strbuf_release(&path);
>         strbuf_release(&rel_path);
>         free((void *)real_work_tree);
>  }
> --
> 2.9.1.566.gbd532d4
>