BUG #5748: Invalid oidvector data during binary recv

The following bug has been logged online:

Bug reference:      5748
Logged by:          Yeb Havinga
Email address:      yebhavinga@gmail.com
PostgreSQL version: 9.0.1
Operating system:   Linux
Description:        Invalid oidvector data during binary recv
Details:

postgres=# create table a as select ''::oidvector;
SELECT 1
postgres=# copy a to '/tmp/test' with binary;
COPY 1
postgres=# copy a from '/tmp/test' with binary;
ERROR:  invalid oidvector data

The error caused by the ARR_LBOUND(result)[0] != 0) check in oidvectorrecv,
and after some debugging and looking at common values of the lbound, I
wonder if this check itself is correct.

regards,
Yeb Havinga