BUG #6083: psql script line numbers incorrectly count \copy data

The following bug has been logged online:

Bug reference: 6083
Logged by: Steve Haslam
Email address: araqnid(at)googlemail(dot)com
PostgreSQL version: 9.0.4
Operating system: Debian GNU/Linux (amd64)
Description: psql script line numbers incorrectly count \copy data
Details:

test_linenumbers.dat:
1
1
2
3
5
8

test_linenumbers.sql:
DO $$ BEGIN RAISE INFO 'Before copy'; END; $$; -- line 1
CREATE TEMP TABLE test_linenumbers_data(value int);
\copy test_linenumbers_data from test_linenumbers.dat
DO $$ BEGIN RAISE INFO 'After copy'; END; $$; -- line 4

Performing "psql -f test_linenumbers.sql" produces:

psql:test_linenumbers.sql:1: INFO: Before copy
DO
CREATE TABLE
psql:test_linenumbers.sql:11: INFO: After copy
DO

However, it seems to me that the second INFO should be reported against
test_linenumbers.sql:4 rather than :11. Apparently, the data read from \copy
is incrementing the script line number counter?

Also occurs with 9.1b2 and a recent 9.2devel.