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=#