surround calls to resources that may or may not be available. Specifying the
expected exception and attributes to be raised if the resource is not available
prevents overly broad catching of exceptions.
This is meant to help suppress spurious failures by raising
test.test_support.ResourceDenied if the exception matches. It would probably
be good to go through the various network tests and surround the calls to catch
connection timeouts (as done with test_socket_ssl in this commit).
I cleaned up whitespace but otherwise didn't change it.
This will need work to reflect the tentative decision to drop nonblocking I/O
support from the buffering layers.
We add some new rules that are required for preserving internal
invariants of types.
1. If type (or a subclass of type) appears in bases, it must appear
before any non-type bases. If a non-type base (like a regular
new-style class) occurred first, it could trick type into
allocating the new class an __dict__ which must be impossible.
2. There are several checks that are made of bases when creating a
type. Those checks are now repeated when assigning to __bases__.
We also add the restriction that assignment to __bases__ may not
change the metaclass of the type.
Add new tests for these cases and for a few other oddball errors that
were no previously tested. Remove a crasher test that was fixed.
Also some internal refactoring: Extract the code to find the most
derived metaclass of a type and its bases. It is now needed in two
places. Rewrite the TypeError checks in test_descr to use doctest.
The tests now clearly show what exception they expect to see.
Also implemented Neal's suggestion (add fileno() to SocketIO)
and some unrelated changes, e.g. remove Google copyright
and make BytesIO a subclass of BufferedIOBase.
Add nonlocal_stmt to Grammar and Nonlocal node to AST. They both
parallel the definitions for globals. The symbol table treats
variables declared as nonlocal just like variables that are free
implicitly.
This change is missing the language spec changes, but makes some
decisions about what the spec should say via the unittests. The PEP
is silent on a number of decisions, so we should review those before
claiming that nonlocal is complete.
Thomas Wouters made the grammer and ast changes. Jeremy Hylton added
the symbol table changes and the tests. Pete Shinners and Neal
Norwitz helped review the code.
