Fix for SF bug #492345. (I could've sworn I checked this in, but
apparently I didn't!)
This code:
class Classic:
pass
class New(Classic):
__metaclass__ = type
attempts to create a new-style class with only classic bases -- but it
doesn't work right. Attempts to fix it so it works caused problems
elsewhere, so I'm now raising a TypeError in this case.
delivered bizarre results. Check float_divmod for a Py_NotImplemented
return and pass it along (instead of treating Py_NotImplemented as a
2-tuple).
CONVERT_TO_DOUBLE: Added comments; this macro is obscure.
PyDict_UpdateFromSeq2(): removed it.
PyDict_MergeFromSeq2(): made it public and documented it.
PyDict_Merge() docs: updated to reveal <wink> that the second
argument can be any mapping object.
no get function was defined, the property's doc string was
inaccessible. This was because the test for prop_get was made
*before* the test for a NULL/None object argument.
Also changed the property class defined in Python in a comment to test
for NULL to decide between get and delete; this makes it less Python
but then, assigning None to a property doesn't delete it!
PyString_FromString():
Since the length of the string is already being stored in size,
changed the strcpy() to a memcpy() for a small speed improvement.
out the for loop at the end intended to zero out new items wasn't
doing anything, because sv->ob_size was already equal to newsize. The
fix slightly refactors the function, introducing a variable oldsize
and doing away with sizediff (which was used only once), and using
oldsize and newsize consistently. I also added comments explaining
what the two for loops do. (Looking at the CVS annotation of this
function, it's no miracle a bug crept in -- this has been patched by
many different folks! :-)
This is best reproduced by
while 1:
class U(unicode):
pass
U(u"xxxxxx")
The unicode_dealloc() code wasn't properly freeing the str and defenc
fields of the Unicode object when freeing a subtype instance. Fixed
this by a subtle refactoring that actually reduces the amount of code
slightly.
PyCell_Set() incremenets the reference count, so the earlier XINCREF
causes a leak.
Also make a number of small performance improvements to the code on
the assumption that most of the time variables are not rebound across
a FastToLocals() / LocalsToFast() pair.
Replace uses of PyCell_Set() and PyCell_Get() with PyCell_SET() and
PyCell_GET(), since the frame is guaranteed to contain cells.
Add a missing DECREF in an obscure corner. If the str() or repr() of
an object passed to a string interpolation -- e.g. "%s" % obj --
returns a non-string, the returned object was leaked.
Repair an indentation glitch.
Replace a bunch of PyString_AsString() calls (and their ilk) with
macros.
It was easier than I thought, assuming that no other things contribute
to the instance size besides slots -- a pretty good bet. With a test
suite, no less!
happy if one could delete the __dict__ attribute of an instance. I
love to make Jim happy, so here goes...
- New-style objects now support deleting their __dict__. This is for
all intents and purposes equivalent to assigning a brand new empty
dictionary, but saves space if the object is not used further.
int_mul(): new and vastly simpler overflow checking. Whether it's
faster or slower will likely vary across platforms, favoring boxes
with fast floating point. OTOH, we no longer have to worry about
people shipping broken LONG_BIT definitions <0.9 wink>.
There's now a new structmember code, T_OBJECT_EX, which is used for
all __slot__ variables (except __weakref__, which has special behavior
anyway). This new code raises AttributeError when the variable is
NULL rather than converting NULL to None.
string object (or a Unicode that's trivially converted to ASCII).
PyObject_GetAttr(): add an 'else' to the Unicode test like
PyObject_SetAttr() already has.
Rather than tweaking the inheritance of type object slots (which turns
out to be too messy to try), this fix adds a __hash__ to the list and
dict types (the only mutable types I'm aware of) that explicitly
raises an error. This has the advantage that list.__hash__([]) also
raises an error (previously, this would invoke object.__hash__([]),
returning the argument's address); ditto for dict.__hash__.
The disadvantage for this fix is that 3rd party mutable types aren't
automatically fixed. This should be added to the rules for creating
subclassable extension types: if you don't want your object to be
hashable, add a tp_hash function that raises an exception.
Also, it's possible that I've forgotten about other mutable types for
which this should be done.
SF patch #480716 by Greg Chapman fixes the problem that super's
__get__ method always returns an instance of super, even when the
instance whose __get__ method is called is an instance of a subclass
of super.
Other issues fixed:
- super(C, C()).__class__ would return the __class__ attribute of C()
rather than the __class__ attribute of the super object. This is
confusing. To fix this, I decided to change the semantics of super
so that it only applies to code attributes, not to data attributes.
After all, overriding data attributes is not supported anyway.
- While super(C, x) carefully checked that x is an instance of C,
super(C).__get__(x) made no such check, allowing for a loophole.
This is now fixed.
slot_tp_descr_set(): When deleting an attribute described by a
descriptor implemented in Python, the descriptor's __del__ method is
called by the slot_tp_descr_set dispatch function. This is bogus --
__del__ already has a different meaning. Renaming this use of __del__
is renamed to __delete__.
Bugfix candidate.
int_repr(): we've never had a buffer big enough to hold the largest
possible result on a 64-bit box. Now that we're using snprintf instead
of sprintf, this can lead to nonsense results instead of random stack
corruption.
pass the buffer length. Stop using it. It should be deprecated, but too
late in the release cycle to do that now.
New static format_float() does the same thing but requires passing the
buffer length too. Use it instead.
const char* instead of char*. The change is conceptually correct, and
indirectly fixes a compiler wng introduced when somebody else innocently
passed a const char* to this function.
sprintf() to PyOS_snprintf() for buffer overrun avoidance.
complex_print(), complex_repr(), complex_str(): Call complex_to_buf()
passing in sizeof(buf).
confusing error messages. If a new-style class has no sequence or
mapping behavior, attempting to use the indexing notation with a
non-integer key would complain that the sequence index must be an
integer, rather than complaining that the operation is not supported.
of multiple inheritance from a mix of new- and classic-style classes.
This is his patch, plus a start at some test cases from me. Will check
in more, plus a NEWS blurb, later tonight.
object, so the "Metroworks only" section should not decref it in case
of error (the caller is responsible for decref'ing in case of error --
and does).
Guido van Rossum
Fred Drake
Tim Peters
Jeremy Hylton
Martin v. Löwis
Jack Jansen
Barry Warsaw
Marc-André Lemburg