locale operation to be invoked, but no collation was derived (in trigger)

Hi,

first i am not sure how the state of the collation work in current git is supposed to be with all the discussion going on here... but wanted to get out that bug report:

create table ad_tab (ad_tab_id varchar(32), name varchar(32));

create function test_trg() RETURNS TRIGGER LANGUAGE plpgsql AS $function$ DECLARE
BEGIN
--Check tab name starts with a upper case letter
IF (not (substr(new.Name,1,1) between 'A' and 'Z')) THEN
RAISE EXCEPTION '%', '@TabName1stCharUpper@' ; --OBTG:-20000--
END IF;
END
; $function$
;

create trigger test_trg after update on test for each row execute procedure test_trg();

insert into test values ('1', 'test');
update test set name = 'test2' where test_id = '1';

ERROR: locale operation to be invoked, but no collation was derived
CONTEXT: PL/pgSQL function "test_trg" line 4 at IF

Regards,
Stefan