Subject: Re: [PATCH 08/16] update submodules: add depopulate_submodule

From: Brandon Williams <[email-masked]>
Date: Fri, 18 Nov 2016 09:46:07 -0800

On 11/17, Stefan Beller wrote:
> On Thu, Nov 17, 2016 at 2:42 PM, Stefan Beller <[email-masked]> wrote:
> >
> > I think I'll just write this functionality in C and optionally expose
> > it via the submodule--helper,
> > such that the user facing git-submodule.sh only has to call that helper.
> 
> I think it will roughly look like this:
> (white space mangled)
> 
> 
> commit e72ef244c667920c874247aa32aa55845500aac8
> Author: Stefan Beller <[email-masked]>
> Date:   Thu Nov 17 16:14:46 2016 -0800
> 
>     submodule--helper: add intern-git-dir function
> 
>     When a submodule has its git dir inside the working dir, the submodule
>     support for checkout that we plan to add in a later patch will fail.
> 
>     Add functionality to migrate the git directory to be embedded
>     into the superprojects git directory.
> 
>     Signed-off-by: Stefan Beller <[email-masked]>
> 
> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index 4beeda5..4f31100 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c
> @@ -1076,6 +1076,21 @@ static int resolve_remote_submodule_branch(int
> argc, const char **argv,
>         return 0;
>  }
> 
> +static int intern_git_dir(int argc, const char **argv, const char *prefix)
> +{
> +       int i;
> +       struct pathspec pathspec;
> +       struct module_list list = MODULE_LIST_INIT;
> +
> +       if (module_list_compute(argc, argv, prefix, &pathspec, &list) < 0)
> +               return 1;
> +
> +       for (i = 0; i < list.nr; i++)
> +               migrate_submodule_gitdir(list.entries[i]->name);
> +
> +       return 0;
> +}
> +
>  struct cmd_struct {
>         const char *cmd;
>         int (*fn)(int, const char **, const char *);
> @@ -1090,7 +1105,8 @@ static struct cmd_struct commands[] = {
>         {"resolve-relative-url", resolve_relative_url},
>         {"resolve-relative-url-test", resolve_relative_url_test},
>         {"init", module_init},
> -       {"remote-branch", resolve_remote_submodule_branch}
> +       {"remote-branch", resolve_remote_submodule_branch},
> +       {"intern-git-dir", intern_git_dir}
>  };
> 
>  int cmd_submodule__helper(int argc, const char **argv, const char *prefix)
> diff --git a/submodule.c b/submodule.c
> index 45b9060..e513bba 100644
> --- a/submodule.c
> +++ b/submodule.c
> @@ -1335,3 +1335,42 @@ void prepare_submodule_repo_env(struct argv_array *out)
>         }
>         argv_array_push(out, "GIT_DIR=.git");
>  }
> +
> +/*
> + * Migrate the given submodule (and all its submodules recursively) from
> + * having its git directory within the working tree to the git dir nested
> + * in its superprojects git dir under modules/.
> + */
> +void migrate_submodule_gitdir(const char *path)
> +{
> +       char *old_git_dir;
> +       const char *new_git_dir;
> +       const struct submodule *sub;
> +
> +       struct child_process cp = CHILD_PROCESS_INIT;
> +       cp.git_cmd = 1;
> +       cp.no_stdin = 1;
> +       cp.dir = path;
> +       argv_array_pushl(&cp.args, "submodule", "foreach", "--recursive",
> +                       "git", "submodule--helper" "intern-git-dir", NULL);
> +
> +       if (run_command(&cp))
> +               die(_("Could not migrate git directory in submodule '%s'"),
> +                   path);
> +
> +       old_git_dir = xstrfmt("%s/.git", path);
> +       if (read_gitfile(old_git_dir))
> +               /* If it is an actual gitfile, it doesn't need migration. */
> +               goto out;
> +
> +       sub = submodule_from_path(null_sha1, path);

This should probably be checked to see if sub not NULL before
dereferencing it right?

> +       new_git_dir = git_common_path("modules/%s", sub->name);
> +
> +       if (rename(old_git_dir, new_git_dir) < 0)
> +               die_errno(_("Could not migrate git directory from %s to %s"),
> +                       old_git_dir, new_git_dir);
> +
> +       connect_work_tree_and_git_dir(path, new_git_dir);
> +out:
> +       free(old_git_dir);
> +}
> diff --git a/submodule.h b/submodule.h
> index aac202c..143ec18 100644
> --- a/submodule.h
> +++ b/submodule.h
> @@ -90,5 +90,6 @@ extern int parallel_submodules(void);
>   * retaining any config in the environment.
>   */
>  extern void prepare_submodule_repo_env(struct argv_array *out);
> +extern void migrate_submodule_gitdir(const char *path);
> 
>  #endif

-- 
Brandon Williams