Re: Small memory fixes for pg_createsubcriber

On Tue, Apr 01, 2025 at 04:28:34PM -0300, Ranier Vilela wrote:
> Em ter., 1 de abr. de 2025 às 15:39, Noah Misch <noah@leadboat.com>
> escreveu:
> 
> > On Thu, Feb 27, 2025 at 10:23:31AM -0300, Ranier Vilela wrote:
> > > Em qui., 27 de fev. de 2025 às 02:51, Michael Paquier <
> > michael@paquier.xyz>
> > > escreveu:
> > >
> > > > On Tue, Feb 25, 2025 at 08:54:31AM -0300, Ranier Vilela wrote:
> > > > > @@ -455,7 +455,9 @@ set_locale_and_encoding(void)
> > > > >   locale->db_locale,
> > > > >   strlen(locale->db_locale));
> > > > >   else
> > > > > - datlocale_literal = pg_strdup("NULL");
> > > > > + datlocale_literal = PQescapeLiteral(conn_new_template1,
> > > > > + "NULL",
> > > > > + strlen("NULL"));

> > This became  2a083ab "pg_upgrade: Fix inconsistency in memory
> > freeing".
> > PQescapeLiteral("NULL") is "'NULL'", so this causes pg_database.datlocale
> > to
> > contain datlocale='NULL'::text instead of datlocale IS NULL.
> >
> I believe the intention of the query is:
> For example:
> UPDATE pg_catalog.pg_database
> SET encoding = 6,
> datlocprovider = 'c',
> datlocale = NULL
> WHERE datname = 'template0';
> 
> Where datlocale with NULL is correct  no?

Right.  Commit 2a083ab changed it to:

  UPDATE pg_catalog.pg_database
  SET encoding = 6,
  datlocprovider = 'c',
  datlocale = 'NULL'
  WHERE datname = 'template0';

> Because:
> UPDATE pg_catalog.pg_database
> SET encoding = 6,
> datlocprovider = 'c',
> datlocale IS NULL
> WHERE datname = 'template0';
> 
> ERROR:  syntax error at or near "IS"
> LINE 4: datlocale IS NULL

Yes, pg_upgrade should not do that.  I was trying to explain the difference
between NULL and 'NULL'.  I didn't mean pg_upgrade should emit "IS NULL".