This is code lifted from variable.c's ParseVariableBool(). When the other patch for "psql hooks" is committed (the one that detects when the string wasn't a valid boolean), this code will go away and we'll just use ParseVariableBool() again.
The ParseVariableBool function has been updated, and the new version is much cleaner, including all fixes that I suggested in your copy, so you can use it in your patch.
-- Fabien. -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers