"Christopher L. Cousins" <chris-pgsql-bugs@cobalt.impulse.net> writes:
>> This bug has probably been there all along, but it'd be pretty
>> low-probability under most circumstances.
> FYI, either postgres 6.3.2 did not have this problem or what I am doing did
> not trigger it in 6.3.2 (I recently upgraded from 6.3.2 to 7.0.2).
The bug is clearly there in 6.3 sources, but it could only fail if
LIKE's input data happened to have been allocated smack up against the
end of application memory. Probably, this has been made more likely by
unrelated changes to our memory management code --- at least, it's more
likely than before for the specific usage pattern embodied in your
example.
regards, tom lane