Re: Add lasterrno setting for dir_existsfile()

On Fri, Aug 12, 2022 at 06:22:01PM -0400, Bruce Momjian wrote:
> On Mon, Jan 10, 2022 at 12:19:28AM +0800, Wei Sun wrote:
> > Hi,
> >
> > Some time ago,the following patch clean up error handling in pg_basebackup's
> > walmethods.c.
> > https://github.com/postgres/postgres/commit/248c3a9
> >
> > This patch keep the error state in the DirectoryMethodData struct,
> > in most functions, the lasterrno is set correctly, but in function
> > dir_existsfile(),
> > the lasterrno is not set when the file fails to open.
> >
> > If this is a correction omission, I think this patch can fix this.
>
> Looking at this, the function is used to check if something exists, and
> return a boolean. I am not sure it is helpful to also return a ENOENT in
> the lasterrno status field. It might be useful to set lasterrno if the
> open fails and it is _not_ ENOENT.

Thinking some more, how would you know to check lasterrno since exists
and not exists are both valid outputs?

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

Indecision is a decision. Inaction is an action. Mark Batterson