Re: [PATCH 04/10] name-rev: don't leak path copy in name_ref()

[Derrick Stolee <stolee@gmail.com>]

On 2/4/2020 4:17 PM, René Scharfe wrote:
> name_ref() duplicates the path string and passes it to name_rev(), which
> either puts it into a commit slab or ignores it if there is already a
> better name, leaking it.  Move the duplication to name_rev() and release
> the copy in the latter case.
> 
> Signed-off-by: René Scharfe <l.s.r@web.de>
> ---
>  builtin/name-rev.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/builtin/name-rev.c b/builtin/name-rev.c
> index 2e6820bd5b..3e22a0503e 100644
> --- a/builtin/name-rev.c
> +++ b/builtin/name-rev.c
> @@ -121,6 +121,8 @@ static void name_rev(struct commit *start_commit,
> 
>  	if (deref)
>  		tip_name = to_free = xstrfmt("%s^0", tip_name);
> +	else
> +		tip_name = to_free = xstrdup(tip_name);

We now unconditionally duplicate the input tip_name and free it
within the method. Good.

>  	if (!create_or_update_name(start_commit, tip_name, taggerdate, 0, 0,
>  				   from_tag)) {
> @@ -323,7 +325,7 @@ static int name_ref(const char *path, const struct object_id *oid, int flags, vo
>  		if (taggerdate == TIME_MAX)
>  			taggerdate = commit->date;
>  		path = name_ref_abbrev(path, can_abbreviate_output);
> -		name_rev(commit, xstrdup(path), taggerdate, from_tag, deref);
> +		name_rev(commit, path, taggerdate, from_tag, deref);

And we no longer duplicate 'path' here, as it is unconditionally duplicated
in name_ref().

Thanks,
-Stolee