Re: [PATCH 1/4] repository.c: move env-related setup code back to environment.c

[Eric Sunshine <sunshine@xxxxxxxxxxxxx>]

On Mon, Feb 26, 2018 at 5:30 AM, Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx> wrote:
> It does not make sense that generic repository code contains handling
> of environment variables, which are specific for the main repository
> only. Refactor repo_set_gitdir() function to take $GIT_DIR and
> optionally _all_ other customizable paths. These optional paths can be
> NULL and will be calculated according to the default directory layout.
>
> Note that some dead functions are left behind to reduce diff
> noise. They will be deleted in the next patch.
>
> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
> ---
> diff --git a/environment.c b/environment.c
> @@ -148,10 +148,17 @@ static char *expand_namespace(const char *raw_namespace)
> -void setup_git_env(void)
> +void setup_git_env(const char *git_dir)
>  {
>         const char *shallow_file;
>         const char *replace_ref_base;
> +       struct set_gitdir_args args = { NULL };
> +
> +       args.shared_root = getenv(GIT_COMMON_DIR_ENVIRONMENT);
> +       args.object_dir = getenv(DB_ENVIRONMENT);
> +       args.graft_file = getenv(GRAFT_ENVIRONMENT);
> +       args.index_file = getenv(INDEX_ENVIRONMENT);

According to POSIX[1], the result of getenv() may be invalidated by
another call to getenv() (or setenv() or unsetenv() or putenv()).

[1]: http://pubs.opengroup.org/onlinepubs/9699919799/functions/getenv.html

> +       repo_set_gitdir(the_repository, git_dir, &args);
> diff --git a/repository.c b/repository.c
> @@ -61,15 +61,50 @@ static void repo_setup_env(struct repository *repo)
> +void repo_set_gitdir(struct repository *repo,
> +                    const char *root,
> +                    const struct set_gitdir_args *o)
> +{
> +       const char *gitfile = read_gitfile(root);
> +       char *old_gitdir = repo->gitdir;
> +
> +       repo->gitdir = xstrdup(gitfile ? gitfile : root);
>         free(old_gitdir);

Can:

    char *old_gitdir = repo->gitdir;
    repo->gitdir = xstrdup(...);
    free(old_gitdir);

be simplified to:

    free(repo->gitdir);
    repo->gitdir = xstrdup(...);

?

> +       repo_set_commondir(repo, o->shared_root);

The repo_set_gitdir() prototype (below) makes it seem as if the last
argument ('o', in this case) is optional, presumably by passing in
NULL, however, this code does not appear to be prepared to deal with
NULL.

> +       expand_base_dir(&repo->objects.objectdir, o->object_dir,
> +                       repo->commondir, "objects");
> +       expand_base_dir(&repo->graft_file, o->graft_file,
> +                       repo->commondir, "info/grafts");
> +       expand_base_dir(&repo->index_file, o->index_file,
> +                       repo->gitdir, "index");
>  }
> diff --git a/repository.h b/repository.h
> @@ -89,7 +89,16 @@ struct repository {
> +struct set_gitdir_args {
> +       [...]
> +};
> +
> +extern void repo_set_gitdir(struct repository *repo,
> +                           const char *root,
> +                           const struct set_gitdir_args *optional);