BUG #15956: Server closed unexpectedly for user-defined base type LIKE char
The following bug has been logged on the website:
Bug reference: 15956
Logged by: Jason Kim
Email address: jj-kim@users.noreply.github.com
PostgreSQL version: 11.4
Operating system: OS X (and CentOS)
Description:
The following causes the server to close unexpectedly.
```
CREATE TYPE char_type;
CREATE FUNCTION char_type_in(cstring) RETURNS char_type
LANGUAGE internal IMMUTABLE STRICT AS 'charin';
CREATE FUNCTION char_type_out(char_type) RETURNS cstring
LANGUAGE internal IMMUTABLE STRICT AS 'charout';
CREATE TYPE char_type (
INPUT = char_type_in,
OUTPUT = char_type_out,
LIKE = char
);
CREATE TABLE char_table (t char_type);
INSERT INTO char_table (t)
VALUES ('t');
```
Here is the server close message:
```
server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.
!> \q
```
This is tested using Postgres v11.4 on OS X and Postgres v9.2.24 on CentOS.
PG Bug reporting form <noreply@postgresql.org> writes:
The following causes the server to close unexpectedly.
CREATE TYPE char_type;
CREATE FUNCTION char_type_in(cstring) RETURNS char_type
LANGUAGE internal IMMUTABLE STRICT AS 'charin';
CREATE FUNCTION char_type_out(char_type) RETURNS cstring
LANGUAGE internal IMMUTABLE STRICT AS 'charout';
CREATE TYPE char_type (
INPUT = char_type_in,
OUTPUT = char_type_out,
LIKE = char
);
CREATE TABLE char_table (t char_type);
INSERT INTO char_table (t)
VALUES ('t');
This is pilot error, not a server bug: you created a type that's
not compatible with the I/O functions you provided for it.
Admittedly, it's a bit of a gotcha: "LIKE = char" interprets
char as bpchar, a/k/a the SQL CHAR(n) type. But the internal
charin and charout functions are for the single-byte "char"
type. If we didn't have a couple decades worth of backward
compatibility to think about, we'd likely rename the latter
type, since it's a Postgres-ism not standard.
regards, tom lane