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.
of some of the common builtin types.
Use a bit in tp_flags for each common builtin type. Check the bit
to determine if any instance is a subclass of these common types.
The check avoids a function call and O(n) search of the base classes.
The check is done in the various Py*_Check macros rather than calling
PyType_IsSubtype().
All the bits are set in tp_flags when the type is declared
in the Objects/*object.c files because PyType_Ready() is not called
for all the types. Should PyType_Ready() be called for all types?
If so and the change is made, the changes to the Objects/*object.c files
can be reverted (remove setting the tp_flags). Objects/typeobject.c
would also have to be modified to add conditions
for Py*_CheckExact() in addition to each the PyType_IsSubtype check.
When running the interpreter in an environment that would cause it to set
stdout/stderr/stdin's encoding, having a sitecustomize that would replace
them with something other than PyFile objects would crash the interpreter.
Fix it by simply ignoring the encoding-setting for non-files.
This could do with a test, but I can think of no maintainable and portable
way to test this bug, short of adding a sitecustomize.py to the buildsystem
and have it always run with it (hmmm....)
* unified the way intobject, longobject and mystrtoul handle
values around -sys.maxint-1.
* in general, trying to entierely avoid overflows in any computation
involving signed ints or longs is extremely involved. Fixed a few
simple cases where a compiler might be too clever (but that's all
guesswork).
* more overflow checks against bad data in marshal.c.
* 2.5 specific: fixed a number of places that were still confusing int
and Py_ssize_t. Some of them could potentially have caused
"real-world" breakage.
* list.pop(x): fixing overflow issues on x was messy. I just reverted
to PyArg_ParseTuple("n"), which does the right thing. (An obscure
test was trying to give a Decimal to list.pop()... doesn't make
sense any more IMHO)
* trying to write a few tests...
Georg Brandl
Jeremy Hylton
Neal Norwitz
Raymond Hettinger
Martin v. Löwis
Brett Cannon
Thomas Wouters
Gustavo Niemeyer
Andrew M. Kuchling
Thomas Heller
Armin Rigo