backend crash with inet type

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POSTGRESQL BUG REPORT TEMPLATE
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Your name : Chris Dunlop
Your email address : chris(at)onthe(dot)net(dot)au

System Configuration
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Architecture (example: Intel Pentium) : Intel-Pentium

Operating System (example: Linux 2.0.26 ELF) : Linux 2.0.35

PostgreSQL version (example: PostgreSQL-6.4) : PostgreSQL-6.4.2, also snapshot-990320

Compiler used (example: gcc 2.8.0) : gcc 2.7.2.3

Please enter a FULL description of your problem:
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Attempting to delete from a table by inet, with rows containing NULL inet
types results in a backend crash

Please describe a way to repeat the problem. Please try to provide a
concise reproducible example, if at all possible:
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create table blah ( ip_address inet );
CREATE

insert into blah values('0.0.0.0');
INSERT 18761 1

delete from blah where ip_address = '111.111.111.111';
DELETE 0

insert into blah values(NULL);
INSERT 18762 1

delete from blah where ip_address = '111.111.111.111';
pqReadData() -- backend closed the channel unexpectedly.
This probably means the backend terminated abnormally
before or while processing the request.
We have lost the connection to the backend, so further processing is impossible. Terminating.

If you know how this problem might be fixed, list the solution below:
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