Re: pg_rewind copies

On 01.04.22 11:00, Daniel Gustafsson wrote:
> One small comment on the patch:
>
> + snprintf(srcpath, sizeof(srcpath), "%s/%s", datadir, path);
>
> This should IMO check the returnvalue of snprintf to ensure it wasn't
> truncated. While the risk is exceedingly small, a truncated filename might
> match another existing filename and the error not getting caught. There is
> another instance just like this one in open_target_file() to which I think we
> should apply the same belts-and-suspenders treatment. I've fixed this in the
> attached version which also have had a pg_indent run on top of a fresh rebase.

We use snprintf() like that countless times, and approximately none of
them check for overflow. So while you are right, this might not be the
place to start a new policy.

If you don't like this approach, use psprintf() perhaps.