Re: fd.c: flush data problems on osx - Mailing list pgsql-hackers

On 2016-04-13 17:44:41 -0400, Tom Lane wrote:
> Andres Freund <andres@anarazel.de> writes:
> > I'm not entirely sure what
> 
> > +   /*
> > +    * Caution: do not call pg_flush_data with amount = 0, it could trash the
> > +    * file's seek position.
> > +    */
> > +   if (amount <= 0)
> > +       return;
> > +
> 
> > is about?
> 
> fd.c tracks seek position for open files.  I'm not sure that that
> function can get called with amount == 0, but if it did, the caller
> would certainly not be expecting the file position to change.

Ok, fair enough.  (And no, it should currently be never called that way)

Andres