BUG #14241: i want to do commit and rollback in one plpgsql block..

The following bug has been logged on the website:

Bug reference: 14241
Logged by: Zubair Alam
Email address: zzia88(at)gmail(dot)com
PostgreSQL version: 9.5.3
Operating system: windows7-x64(64 bit)
Description:

CREATE OR REPLACE FUNCTION DELROLL()
RETURNS INT AS $V_CHOICE$
BEGIN
IF V_CHOICE=1 THEN
DELETE FROM ITEMS
WHERE itemid=4;
--DBMS_OUTPUT.PUT_LINE('EMPLYEE RECORD DELETED
SUCESSFULLY');
END IF;
IF V_CHOICE=2 THEN
ROLLBACK;
COMMIT;
---DBMS_OUTPUT.PUT_LINE('ROLL BACK COMPLETED SUCESSFULLY');
END IF;
RETURN V_CHOICE;
END;
$V_CHOICE$
LANGUAGE PLPGSQL;

when i enter my choice 2 i.e for rollback and commit then that time this
error is generating.
ERROR: current transaction is aborted, commands ignored until end of
transaction block

********** Error **********

ERROR: current transaction is aborted, commands ignored until end of
transaction block
SQL state: 25P02

please give me perfect solution for using commit and rollback in one
plpgsql program block.