Re: [PATCH] fast-import: disallow "." and ".." path components

[Eric Sunshine <sunshine@sunshineco.com>]

On Mon, Nov 25, 2024 at 12:58 PM Elijah Newren via GitGitGadget
<gitgitgadget@gmail.com> wrote:
> If a user specified e.g.
>    M 100644 :1 ../some-file
> then fast-import previously would happily create a git history where
> there is a tree in the top-level directory named "..", and with a file
> inside that directory named "some-file".  The top-level ".." directory
> causes problems.  While git checkout will die with errors and fsck will
> report hasDotdot problems, the user is going to have problems trying to
> remove the problematic file.  Simply avoid creating this bad history in
> the first place.
>
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
> diff --git a/builtin/fast-import.c b/builtin/fast-import.c
> @@ -1466,6 +1466,9 @@ static int tree_content_set(
>         e->name = to_atom(p, n);
> +       if (!strcmp(e->name->str_dat, ".") || !strcmp(e->name->str_dat, "..")) {
> +               die("path %s contains invalid component", p);
> +       }

Probably not worth a reroll, but is_dot_or_dotdot() might be usable here.

(And -- style nit -- the braces could be dropped.)