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.
Fixes bug 1569356, but at the cost of a minor incompatibility in
locals(). Add test that verifies that the class namespace is not
polluted. Also clarify the behavior in the library docs.
Along the way, cleaned up the dict_to_map and map_to_dict
implementations and added some comments that explain what they do.
calling __import__. This helps make the expected search locations for encoding
modules be more explicit.
One could use an explicit value for __path__ when making the call to __import__
to force the exact location searched for encodings. This would give the most
strict search path possible if one is worried about malicious code being
imported. The unfortunate side-effect of that is that if __path__ was modified
on 'encodings' on purpose in a safe way it would not be picked up in future
__import__ calls.
mouse and cursor selection in ACWindow implemented; double Tab inserts current
selection and closes ACW (similar to double-click and Return); scroll wheel now
works in ACW. Added AutoComplete instructions to IDLE Help.
Suggested solution by Christos Georgiou, Bug 791968.
2. Clean up tests, were not failing when they should have been.
4. Remove some camelcase and an unneeded try/except block.
The next step of PEP 352 (for 2.6) causes raising a string exception to trigger
a TypeError. Trying to catch a string exception raises a DeprecationWarning.
References to string exceptions has been removed from the docs since they are
now just an error.