Updated openstack/openstack
Project: openstack/oslo.db  5e2e96aca049cde2717441a5a4ea8027d9eec52a

Add _wrap_db_error support for postgresql

The original "_wrap_db_error" function is only available for mysql.
We need to add support for postgresql.

The deadlock exception thrown from postgresql is TransactionRollbackError,
it's not the same with "OperationalError" thrown from mysql,
and isn't included in sqlalchemy. So, the base exception need to be
catched.

Change-Id: I439a4e0c431c9446ffabd1c93f11b8f509b1ebd7
Closes-Bug: #1270725
Updated openstack/openstack
Project: openstack/oslo.rootwrap  e202a03a6e77c7ccdbc797364307a0cbf1016ff6

Avoid usage of mutables as default args

Passing mutable objects as default args is a known Python pitfall.
We'd better avoid this. This commit changes mutable default args with
None, then use 'arg = arg or []'.

Change-Id: I1f1989d5da934d959aeafecf7165e71dfaa500e6