So you think psql should issue "COMMIT;" even if it is exiting due to
"ON_ERROR_STOP"?
I say yes, if it is a non-SQL error. As Viktor stated, SQL errors abort the transaction.
Ok, so we disagree here because that distinction seems arbitrary and decidedly not useful.
Whether you do or don't can you show me where in the documentation the current behavior is described?
Your biggest issue seems to be with --single-transaction and ON_ERROR_STOP so:
--single-transaction
When psql executes a script, adding this option wraps BEGIN/COMMIT around the script to execute it as a single transaction.
Therefore:
BEGIN; script COMMIT;
I would and have agreed with your previous statements that it is not clear enough that \i is not an SQL command and an error with same is ignored by the transaction. Outside of that I see no problem.
That still leaves ambiguity. How about:
--single-transaction
When psql executes a script using this option it explicitly begins a transaction at session start and commits that transaction at session end. The transaction will commit even if the script is forced to exit early due to ON_ERROR_STOP: and if no SQL errors have occurred all statements prior to the error-inducing psql meta-command will be committed. For this reason it is not recommended to combine this option and ON_ERROR_STOP - instead omit this option and supply the transaction commands yourself.
ON_ERROR_STOP
[existing wording]
As described under the --single-transaction option the commit issued at session end will occur prior to psql exiting and could result in running script being partially committed.