BUG #14499: pg_dump error on the table with 512M or bigger bytea values

The following bug has been logged on the website:

Bug reference: 14499
Logged by: Nikolay Nikitin
Email address: nikolay(dot)nikitin(at)infowatch(dot)com
PostgreSQL version: 9.4.10
Operating system: Red Hat Enterprise Linux Server release 6.7
Description:

Hi! I made test table with one bytea column and insert one record with 512M
or bigger value.

drop table if exists test;

create table test
(
blob bytea
);

insert into test(blob) select string_agg(gen_random_bytes(1024),
null::bytea)::bytea from generate_series(1, 1024 * 512) g;

Try to dump table:

su postgres -c "rm -rf /tmp/test && mkdir /tmp/test && pg_dump -p 5432 -U
postgres -Fd -f /tmp/test -t test postgres"

pg_dump: Dumping the contents of table "test" failed: PQgetResult()
failed.
pg_dump: Error message from server: ERROR: invalid memory alloc request
size 1073741827
pg_dump: The command was: COPY public.test (blob) TO stdout;

If I create table with one 511M bytea value then dump works without
errors.
But I want to dump tables with many 1G bytea values.

Regards, Nikolay.