BUG #6411: Backend process' crash when a foreign table is used in a dependent subquery on select clause

The following bug has been logged on the website:

Bug reference: 6411
Logged by: Using a Foreign Table in a Dependent Subquery
Email address: emre(dot)hasegeli(at)tart(dot)com(dot)tr
PostgreSQL version: 9.1.2
Operating system: Linux 3.0.0-14-generic #23-Ubuntu SMP Mon Nov 21 2
Description:

I installed Dave Page's MySQL Foreign Data Wrapper on GitHub [1]. It works
fine until foreign table is used in a dependent subquery on select clause.

How to reproduce:

Create extension mysql_fdw;

Create server AMySQLServer
foreign data wrapper mysql_fdw
options (address '***', port '3306');

Create user mapping for public
server AMySQLServer
options (username '***', password '***');

Create foreign table AForeignTable (id integer) server AMySQLServer options
(query 'Select id from ASchema.ATable');

Select id, (select true from AForeignTable where AForeignTable.id =
ATable.id) from ATable;

WARNING: 57P02: terminating connection because of crash of another server
process
DETAIL: The postmaster has commanded this server process to roll back the
current transaction and exit, because another server process exited
abnormally and possibly corrupted shared memory.
HINT: In a moment you should be able to reconnect to the database and
repeat your command.

[1] https://github.com/dpage/mysql_fdw