default to to ON_ERROR_STOP=on (Re: psql: exit status with multiple -c and -f)

On Mon, Dec 06, 2021 at 09:08:56AM -0600, Justin Pryzby wrote:
> I raised this issue a few years ago.
> https://www.postgresql.org/message-id/20181217175841.GS13019%40telsasoft.com
>
> |[pryzbyj(at)database ~]$ psql -v VERBOSITY=terse ts -xtc 'ONE' -c "SELECT 'TWO'"; echo "exit status $?"
> |ERROR: syntax error at or near "ONE" at character 1
> |?column? | TWO
> |
> |exit status 0
>
> The documentation doen't say what the exit status should be in this case:
> | psql returns 0 to the shell if it finished normally, 1 if a fatal error of its own occurs (e.g., out of memory, file not found), 2 if the connection to the server went bad and the session was not interactive, and 3 if an error occurred in a script and the variable ON_ERROR_STOP was set.
>
> It returns 1 if the final command fails, even though it's not a "fatal error"
> (it would've happily kept running more commands).
>
> | x=`some_command_that_fails`
> | rm -fr "$x/$y # removes all your data
>
> | psql -c "begin; C REATE TABLE newtable(LIKE oldtable) INSERT INTO newtable SELECT * FROM oldtable; commit" -c "DROP TABLE oldtable
> | psql -v VERBOSITY=terse ts -xtc '0CREATE TABLE newtbl(i int)' -c 'INSERT INTO newtbl SELECT * FROM tbl' -c 'DROP TABLE IF EXISTS tbl' -c 'ALTER TABLE newtbl RENAME TO tbl'; echo ret=$?
>
> David J suggested to change the default value of ON_ERROR_STOP. The exit
> status in the non-default case would have to be documented. That's one
> solution, and allows the old behavior if anybody wants it. That probably does
> what most people want, too. This is more likely to expose a real problem that
> someone would have missed than to break a legitimate use. That doesn't appear
> to break regression tests at all.

I was wrong - the regression tests specifically exercise failure cases, so the
scripts must continue after errors.

I think the current behavior of the regression test SQL scripts is exactly the
opposite of what's desirable for almost all other scripts. The attached makes
ON_ERROR_STOP the default, and runs the regression tests with ON_ERROR_STOP=0.

Is it viable to consider changing this ?