bug in permission handling?

Should the permissions of a deleted user get assigned to a new user
as in the example below?

Martin

$ createdb test
CREATE DATABASE
$ psql test
Welcome to psql, the PostgreSQL interactive terminal.

Type: \copyright for distribution terms
\h for help with SQL commands
\? for help on internal slash commands
\g or terminate with semicolon to execute query
\q to quit

test=# create table abc(a int, b int);
CREATE
test=# select relacl from pg_class where relname='abc';
relacl
--------

(1 row)

test=# create user martin;
CREATE USER
test=# grant all on abc to martin;
GRANT
test=# select relacl from pg_class where relname='abc';
relacl
-------------------------------------
{=,postgres=arwdRxt,martin=arwdRxt}
(1 row)

test=# drop user martin;
DROP USER
test=# select relacl from pg_class where relname='abc';
relacl
----------------------------------
{=,postgres=arwdRxt,101=arwdRxt}
(1 row)

test=# create user tom;
CREATE USER
test=# select relacl from pg_class where relname='abc';
relacl
----------------------------------
{=,postgres=arwdRxt,tom=arwdRxt}
(1 row)

test=# select version();
version
---------------------------------------------------------------------
PostgreSQL 7.2b4 on i386-unknown-freebsd4.3, compiled by GCC 2.95.3
(1 row)

test=#