OverflowError: can't convert negative value to uint32_t

[eheien]

• asyncpg version: 0.15.0
• PostgreSQL version: PostgreSQL 9.5.10 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.2 20140120 (Red Hat 4.8.2-16), 64-bit (AWS RDS version)
  PostgreSQL 9.5.2 on x86_64-pc-linux-gnu, compiled by gcc (Alpine 6.3.0) 6.3.0, 64-bit (local)
• Do you use a PostgreSQL SaaS? If so, which? Can you reproduce
  the issue with a local PostgreSQL install?: Yes, AWS RDS. Local install of PostgreSQL does not have the problem.
• Python version: 3.6.4
• Platform: Red Hat 4.8.5-16
• Do you use pgbouncer?: no
• Did you install asyncpg with pip?: yes
• If you built asyncpg locally, which version of Cython did you use?: n/a
• Can the issue be reproduced under both asyncio and
  uvloop?: did not try

db_asyncpg.py:97: in connection_init_func
                await connection.set_type_codec('geometry', schema='public',
                                                encoder=geom_encoder_ogr, decoder=geom_decoder_ogr,
                                                format='binary')
/usr/lib64/python3.6/site-packages/asyncpg/connection.py:914: in set_type_codec
    encoder, decoder, format)
asyncpg/protocol/settings.pyx:35: in asyncpg.protocol.protocol.ConnectionSettings.add_python_codec
    ???
asyncpg/protocol/settings.pyx:56: in asyncpg.protocol.protocol.ConnectionSettings.add_python_codec
    ???
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

>   ???
E   OverflowError: can't convert negative value to uint32_t

asyncpg/protocol/codecs/base.pyx:541: OverflowError

We constantly create and tear down test DBs, and I believe the problem is that OIDs constantly increase. With the type introspection query on namespace public and type geometry I get the following in the local DB:
7124428 0 b
and the following in the DB that has the failure:
2573727724 0 b

You can see the second OID will overflow to negative if cast as an int. I'm not sure what the solution is, but I'm pretty sure this is the cause of the failure.

[elprans]

Good catch. This should be easy to fix. That said, once you hit the 4 billion OIDs mark, the OID generator will wrap around, and you'll start at 1 again, which may cause other issues.

[eheien]

@elprans Thank you very much for the fix! Do you know roughly when this will be put in a release?

[elprans]

I'm hoping to do a release over the weekend or early next week.