Re: [PATCH v8] format-patch: allow a non-integral version numbers

[ZheNing Hu <adlternative@gmail.com>]

Eric Sunshine <sunshine@sunshineco.com> 于2021年3月21日周日 下午12:05写道：
>
> On Sat, Mar 20, 2021 at 10:56 AM ZheNing Hu via GitGitGadget
> <gitgitgadget@gmail.com> wrote:
> > diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
> > @@ -221,6 +221,11 @@ populated with placeholder text.
> > +        `<n>` may be a non-integer number.  E.g. `--reroll-count=4.4`
> > +       may produce `v4.4-0001-add-makefile.patch` file that has
> > +       "Subject: [PATCH v4.4 1/20] Add makefile" in it.
> > +       `--reroll-count=4rev2` may produce `v4rev2-0001-add-makefile.patch`
> > +       file that has "Subject: [PATCH v4rev2 1/20] Add makefile" in it.
>
> This new example raises the question about what happens if the
> argument to --reroll-count contains characters which don't belong in
> pathnames. For instance, what happens if `--reroll-count=1/2` is
> specified? Most likely, it will fail trying to write the
> "v1/2-whatever.patch" file to a nonexistent directory named "v1".
>
> > diff --git a/log-tree.c b/log-tree.c
> > @@ -369,8 +369,8 @@ void fmt_output_subject(struct strbuf *filename,
> > +       if (info->reroll_count)
> > +               strbuf_addf(filename, "v%s-", info->reroll_count);
> >         strbuf_addf(filename, "%04d-%s", nr, subject);
>
> To protect against that problem, you may need to call
> format_sanitized_subject() manually after formatting "v%s-". (I'm just
> looking at this code for the first time, so I could be hopelessly
> wrong. There may be a better way to fix it.)

Hi, Eric,
This is a kind of "injection" problem,
thank you for your discovery and solution method.