Re: [Segmentation fault] pg_dump binary-upgrade fail for type without element

PFA patch patch for the master branch.

On Thu, Oct 16, 2014 at 11:09 AM, Rushabh Lathia <rushabh(dot)lathia(at)gmail(dot)com>
wrote:

> Hi All,
>
> pg_dump binary-upgrade fail with segmentation fault for type without
> element.
>
> Consider the following testcase:
>
> rushabh(at)postgresql$ ./db/bin/psql postgres
> psql (9.5devel)
> Type "help" for help.
>
> postgres=# drop type typ;
> DROP TYPE
> postgres=# create type typ as ();
> CREATE TYPE
> postgres=# \q
> rushabh(at)postgresql$ ./db/bin/pg_dump postgres --binary-upgrade
> pg_dump: row number 0 is out of range 0..-1
> Segmentation fault (core dumped)
>
> Stake trace:
>
> (gdb) bt
> #0 0x0000003a2cc375f2 in ____strtoull_l_internal () from /lib64/libc.so.6
> #1 0x0000000000417a08 in dumpCompositeType (fout=0x1365200,
> tyinfo=0x13b1340) at pg_dump.c:9356
> #2 0x00000000004156a2 in dumpType (fout=0x1365200, tyinfo=0x13b1340) at
> pg_dump.c:8449
> #3 0x0000000000414b08 in dumpDumpableObject (fout=0x1365200,
> dobj=0x13b1340) at pg_dump.c:8135
> #4 0x00000000004041f8 in main (argc=3, argv=0x7fff838ff6e8) at
> pg_dump.c:812
>
> Into dumpCompositeType(), query fetch the elements for the composite type,
> but in case there are no elements for the type then it returns zero rows.
> In
> the following code block:
>
> if (binary_upgrade)
> {
> Oid typrelid = atooid(PQgetvalue(res, 0, i_typrelid));
>
> binary_upgrade_set_type_oids_by_type_oid(fout, q,
> tyinfo->dobj.catId.oid);
> binary_upgrade_set_pg_class_oids(fout, q, typrelid, false);
> }
>
> it fetching the typrelid which require for binary_upgrade. But in case
> query
> is returning zero rows (for the composite type without element) is failing.
>
> Looking further into code I found that rather then fetching typrelid, we
> can
> use the already stored typrelid from TypeInfo structure.
>
> Following commit added code related to binary_upgrade:
>
> commit 28f6cab61ab8958b1a7dfb019724687d92722538
> Author: Bruce Momjian <bruce(at)momjian(dot)us>
> Date: Wed Jan 6 05:18:18 2010 +0000
>
> binary upgrade:
>
> Preserve relfilenodes for views and composite types --- even though we
> don't store data in, them, they do consume relfilenodes.
>
> Bump catalog version.
>
> PFA patch to fix the issue. I think this need to fix in the back branch as
> well
> because its effecting pg_upgrade. Fix should backport till PG91, as on PG90
> it was not allowed to create type without element.
>
> postgres=# select version();
>
> version
>
> -------------------------------------------------------------------------------------------------------------------
> PostgreSQL 9.0.18 on x86_64-unknown-linux-gnu, compiled by GCC gcc (GCC)
> 4.4.7 20120313 (Red Hat 4.4.7-4), 64-bit
> (1 row)
> postgres=# create type typ as ();
> ERROR: syntax error at or near ")"
> LINE 1: create type typ as ();
> ^
>
> Regards,
> Rushabh Lathia
> www.EnterpriseDB.com
>

--
Rushabh Lathia