Re: [Outreachy] [PATCH] bisect--helper: avoid free-after-use

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Dec 9, 2019, 09:33 UTC
Message-ID: <nycvar.QRO.7.76.6.1912091030310.31080@tvgsbejvaqbjf.bet>
In-Reply-To: <20191209084022.18650-1-mirucam@gmail.com>

Hi Miriam,

just a little note on the process: the convention on the Git mailing list is to use `[PATCH v2]`, `[PATCH v3]`, etc when sending revised patch series. It is even available in `git format-patch`'s options: `-v 2` (see https://git-scm.com/docs/git-format-patch#Documentation/git-format-patch.txt--vltngt)

On Mon, 9 Dec 2019, Miriam Rubio wrote:

Show 16 quoted lines

> From: Tanushree Tumane <tanushreetumane@gmail.com>
>
> In 5e82c3dd22a (bisect--helper: `bisect_reset` shell function in C,
> 2019-01-02), the `git bisect reset` subcommand was ported to C. When the
> call to `git checkout` failed, an error message was reported to the
> user.
>
> However, this error message used the `strbuf` that had just been
> released already. Let's switch that around: first use it, then release
> it.
>
> Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
> Mentored-by: Christian Couder <chriscool@tuxfamily.org>
> Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
> Signed-off-by: Miriam Rubio <mirucam@gmail.com>
> ---

ACK!

Thanks, Dscho

Show 27 quoted lines

>  builtin/bisect--helper.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
> index 1fbe156e67..3055b2bb50 100644
> --- a/builtin/bisect--helper.c
> +++ b/builtin/bisect--helper.c
> @@ -169,11 +169,12 @@ static int bisect_reset(const char *commit)
>
>  		argv_array_pushl(&argv, "checkout", branch.buf, "--", NULL);
>  		if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
> +			error(_("could not check out original"
> +				" HEAD '%s'. Try 'git bisect"
> +				" reset <commit>'."), branch.buf);
>  			strbuf_release(&branch);
>  			argv_array_clear(&argv);
> -			return error(_("could not check out original"
> -				       " HEAD '%s'. Try 'git bisect"
> -				       " reset <commit>'."), branch.buf);
> +			return -1;
>  		}
>  		argv_array_clear(&argv);
>  	}
> --
> 2.21.0 (Apple Git-122.2)
>
>