Re: [PATCH 19/22] userdiff: fix leaking memory for configured diff drivers

> Refactor the code such that we have two pointers for each of these
> strings: one that holds the value as accessed by other subsystems, and
> one that points to the same string in case it has been allocated. Like
> this, we can safely free the second pointer and thus plug those memory
> leaks.
>
> diff --git a/userdiff.c b/userdiff.c
> index c4ebb9ff73..989629149f 100644
> --- a/userdiff.c
> +++ b/userdiff.c
> @@ -399,8 +399,11 @@ static struct userdiff_driver *userdiff_find_by_namelen(const char *name, size_t
>  static int parse_funcname(struct userdiff_funcname *f, const char *k,
>  		const char *v, int cflags)
>  {
> -	if (git_config_string((char **) &f->pattern, k, v) < 0)
> +	f->pattern = NULL;
> +	FREE_AND_NULL(f->pattern_owned);
> +	if (git_config_string(&f->pattern_owned, k, v) < 0)
>  		return -1;
> +	f->pattern = f->pattern_owned;
>  	f->cflags = cflags;
>  	return 0;
>  }