Re: Postmaster crashes on SIGHUP when oauth_validator_libraries holds only whitespace

Hi Daniel,

You're right. I would rather not treat NULL as an empty setting, since
that would turn an internal programming error into the user-facing
"must be set" error. Attached v3 adds:

Assert(oauth_validator_libraries_string != NULL);

before the pstrdup().

I also moved the whitespace-only TAP case to after the
pg_hba_file_rules() check. Its previous position made the test racy:
wait_for_log() synchronized with the postmaster reload, but not
necessarily with the process-local GUC state of the existing bgconn.
As a result, pg_hba_file_rules() could run in a backend that still had
the whitespace value loaded and return unexpected empty fields.

Moving the case after that assertion avoids making the
pg_hba_file_rules() result depend on the timing of SIGHUP processing in
bgconn. After restoring the setting, the test runs SHOW
oauth_validator_libraries through bgconn, ensuring that the backend has
processed the second SIGHUP before the later tests continue.

Thanks,
Yuriy