-----

- Issue 42532: Remove unexpected call of ``__bool__`` when passing a
``spec_arg`` argument to a Mock.

- Issue 39966: Revert bpo-25597. :class:`unittest.mock.MagicMock` with
wraps' set uses default return values for magic methods.

- Issue 41877: Mock objects which are not unsafe will now raise an
AttributeError if an attribute with the prefix asert, aseert, or assrt is
accessed, in addition to this already happening for the prefixes assert or
assret.

- Issue 40126: Fixed reverting multiple patches in unittest.mock. Patcher's
``__exit__()`` is now never called if its ``__enter__()`` is failed.
Returning true from ``__exit__()`` silences now the exception.