Re: [PATCH] small memory leak fix

[Stefan Beller <sbeller@google.com>]

On Mon, May 1, 2017 at 1:40 PM, David CARLIER <devnexen@gmail.com> wrote:
> Hi this is my first submission, a memory leak found in the maint branch (might be in master as well).
>
> Kind regards.

Hi and welcome to Git!

> From d98f3944780730447f111a4178c9d99f5110c260 Mon Sep 17 00:00:00 2001
> From: David Carlier <devnexen@gmail.com>
> Date: Mon, 1 May 2017 21:14:09 +0100
> Subject: [PATCH] memory leaks fixes for remote lists.

We usually word the subject line as "area: what we do"
(C.f. $ git log --oneline --no-merges -- remote.c)
Maybe:

    remote.c: plug memleak in for_each_remote

>
> both push and fetch lists were not freed thus
> using free_refspecs usage.
>
> Signed-off-by: David Carlier <devnexen@gmail.com>
> ---
> remote.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/remote.c b/remote.c
> index 9f83fe2c4..2f8cb35a3 100644
> --- a/remote.c
> +++ b/remote.c
> @@ -742,6 +742,8 @@ int for_each_remote(each_remote_fn fn, void *priv)
>  r->push = parse_push_refspec(r->push_refspec_nr,
>      r->push_refspec);
>  result = fn(r, priv);
> + free_refspecs(r->push, r->push_refspec_nr);
> + free_refspecs(r->fetch, r->fetch_refspec_nr);

After freeing the refspec, r->push/fetch still points to
the (now free'd) memory. We'd want to reset it to NULL as well,
such that e.g. in this function

    if (!r->fetch)
        ...

still works.

After reading this, I think we'd rather want to keep the fetch/push refspec
around for the next access of the struct remote, and only free the memory
when the remote itself is freed?

That however is a problem as we never free them, they are globals :(

Thanks,
Stefan