Bug in GET STACKED DIAGNOSTICS ?

Hi !

I'm running "PostgreSQL 9.2.2 on i686-pc-linux-gnu, compiled by gcc
(Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3, 32-bit" on ubuntu 12.04 .

I'm a bit perplexed by the difference in PG_EXCEPTION_CONTEXT of the
following two invocations of a function where I try to get the call stack.
Is this expected behaviour ?

First invocation (This is the one where I get the expected notification):

select * from testfunc2(true);

NOTICE: PL/pgSQL function testfunc(boolean) line 8 at assignment
PL/pgSQL function testfunc2(boolean) line 6 at RETURNs

Second invocation (I did expect two rows of callstack here also but I only
got one):

select * from testfunc2(false);

NOTICE: PL/pgSQL function testfunc2(boolean) line 6 at RETURNs

The functions:

CREATE OR REPLACE FUNCTION testfunc( div_by_zero boolean )
RETURNS text AS
$BODY$
DECLARE
td text;
i int = 0;
BEGIN
BEGIN
IF div_by_zero THEN
i = 1/i;
ELSE
RAISE EXCEPTION 'an exception';
END IF;
EXCEPTION WHEN raise_exception OR division_by_zero THEN
GET STACKED DIAGNOSTICS td = PG_EXCEPTION_CONTEXT;
RAISE NOTICE '%s',td;
END;
RETURN td::text;
END;
$BODY$
LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION testfunc2(div_by_zero boolean)
RETURNS text AS
$BODY$
DECLARE
td text;
i int = 0;
BEGIN
return testfunc(div_by_zero);
END;
$BODY$
LANGUAGE plpgsql;

Best Regards
Dan S