Windows when n is too big to fit in a 32-bit int. This was a hole in
2.2's large file support on Windows, and turns out it's a bad hole at
least for ZODB.
Repair widespread misuse of _PyString_Resize. Since it's clear people
don't understand how this function works, also beefed up the docs. The
most common usage error is of this form (often spread out across gotos):
if (_PyString_Resize(&s, n) < 0) {
Py_DECREF(s);
s = NULL;
goto outtahere;
}
The error is that if _PyString_Resize runs out of memory, it automatically
decrefs the input string object s (which also deallocates it, since its
refcount must be 1 upon entry), and sets s to NULL. So if the "if"
branch ever triggers, it's an error to call Py_DECREF(s): s is already
NULL! A correct way to write the above is the simpler (and intended)
if (_PyString_Resize(&s, n) < 0)
goto outtahere;
Bugfix candidate.
Original patch(es):
python/dist/src/Objects/fileobject.c:2.161
python/dist/src/Objects/stringobject.c:2.161
python/dist/src/Objects/unicodeobject.c:2.147
open_the_file: Some (not all) flavors of Windows set errno to EINVAL
when passed a syntactically invalid filename. Python turned that into an
incomprehensible complaint about the mode string. Fixed by special-casing
MSVC.
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.
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).
The C-code in fileobject.readinto(buffer) which parses
the arguments assumes that size_t is interchangeable
with int:
size_t ntodo, ndone, nnow;
if (f->f_fp == NULL)
return err_closed();
if (!PyArg_Parse(args, "w#", &ptr, &ntodo))
return NULL;
This causes a problem on Alpha / Tru64 / OSF1 v5.1
where size_t is a long and sizeof(long) != sizeof(int).
The patch I'm proposing declares ntodo as an int. An
alternative might be to redefine w# to expect size_t.
[We can't change w# because there are probably third party modules
relying on it. GvR]
The problem is that if fread() returns a short count, we attempt
another fread() the next time through the loop, and apparently glibc
clears or ignores the eof condition so the second fread() requires
another ^D to make it see the eof condition.
According to the man page (and the C std, I hope) fread() can only
return a short count on error or eof. I'm using that in the band-aid
solution to avoid calling fread() a second time after a short read.
Note that xreadlines() still has this problem: it calls
readlines(sizehint) until it gets a zero-length return. Since
xreadlines() is mostly used for reading real files, I won't worry
about this until we get a bug report.
lseek(fp, 0L, SEEK_CUR) can make a filedescriptor unusable.
This workaround is expected to last only a few weeks (until GUSI
is fixed), but without it test_email fails.
many types were subclassable but had a xxx_dealloc function that
called PyObject_DEL(self) directly instead of deferring to
self->ob_type->tp_free(self). It is permissible to set tp_free in the
type object directly to _PyObject_Del, for non-GC types, or to
_PyObject_GC_Del, for GC types. Still, PyObject_DEL was a tad faster,
so I'm fearing that our pystone rating is going down again. I'm not
sure if doing something like
void xxx_dealloc(PyObject *self)
{
if (PyXxxCheckExact(self))
PyObject_DEL(self);
else
self->ob_type->tp_free(self);
}
is any faster than always calling the else branch, so I haven't
attempted that -- however those types whose own dealloc is fancier
(int, float, unicode) do use this pattern.
no backwards compatibility to worry about, so I just pushed the
'closure' struct member to the back -- it's never used in the current
code base (I may eliminate it, but that's more work because the getter
and setter signatures would have to change.)
As examples, I added actual docstrings to the getset attributes of a
few types: file.closed, xxsubtype.spamdict.state.
compatibility, this required all places where an array of "struct
memberlist" structures was declared that is referenced from a type's
tp_members slot to change the type of the structure to PyMemberDef;
"struct memberlist" is now only used by old code that still calls
PyMember_Get/Set. The code in PyObject_GenericGetAttr/SetAttr now
calls the new APIs PyMember_GetOne/SetOne, which take a PyMemberDef
argument.
As examples, I added actual docstrings to the attributes of a few
types: file, complex, instance method, super, and xxsubtype.spamlist.
Also converted the symtable to new style getattr.
A surprising number of changes to split tp_new into tp_new and tp_init.
Turned out the older PyFile_FromFile() didn't initialize the memory it
allocated in all (error) cases, which caused new sanity asserts
elsewhere to fail left & right (and could have, e.g., caused file_dealloc
to try decrefing random addresses).
