Re: getting "shell command argument contains a newline or carriage return:" error with pg_dumpall when db name have new line in double quote - Mailing list pgsql-hackers

On Fri, 28 Mar 2025 at 01:37, Mahendra Singh Thalor <mahi6run@gmail.com> wrote:
>
> On Thu, 27 Mar 2025 at 18:33, Álvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> >
> > On 2025-Mar-27, Andrew Dunstan wrote:
> >
> > > I don't think we can backpatch this. It's a behaviour change.
> >
> > I agree, we can't.
> >
> > Also, if we're going to enforce this rule, then pg_upgrade --check needs
> > to alert users that they have a database name that's no longer valid.
> > That needs to be part of this patch as well.  We should also ensure that
> > these are the only problem characters, which IMO means it should add a
> > test for pg_dumpall that creates a database whose name has all possible
> > characters and ensures that it is dumpable.
> >
> > --
> > Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/
> > "La virtud es el justo medio entre dos defectos" (Aristóteles)
>
> Thanks Álvaro.
>
> Yes, I also agree with you. "pg_upgrade --check" should alert users regarding database names because pg_upgrade is failing if we have \n\r in dbname(old cluster).
>
> pg_upgrade --check: This is passing but pg_upgrade is failing.
> ............
> Checking for new cluster tablespace directories               ok
> *Clusters are compatible*
>
> pg_upgrade:
> .........................
> Creating dump of global objects                               ok
> Creating dump of database schemas                            
> shell command argument contains a newline or carriage return: "dbname='invalid
> db'"

In the attached patch, instead of the above error, we will get proper ALERT for invalid names even with "pg_upgrade --check" also.

Ex: