In the private pathlib ABCs, support write-only virtual filesystems by
making `WritablePath` inherit directly from `JoinablePath`, rather than
subclassing `ReadablePath`.
There are two complications:
- `ReadablePath.open()` applies to both reading and writing
- `ReadablePath.copy` is secretly an object that supports the *read* side
of copying, whereas `WritablePath.copy` is a different kind of object
supporting the *write* side
We untangle these as follow:
- A new `pathlib._abc.magic_open()` function replaces the `open()` method,
which is dropped from the ABCs but remains in `pathlib.Path`. The
function works like `io.open()`, but additionally accepts objects with
`__open_rb__()` or `__open_wb__()` methods as appropriate for the mode.
These new dunders are made abstract methods of `ReadablePath` and
`WritablePath` respectively. If the pathlib ABCs are made public, we
could consider blessing an "openable" protocol and supporting it in
`io.open()`, removing the need for `pathlib._abc.magic_open()`.
- `ReadablePath.copy` becomes a true method, whereas `WritablePath.copy` is
deleted. A new `ReadablePath._copy_reader` property provides a
`CopyReader` object, and similarly `WritablePath._copy_writer` is a
`CopyWriter` object. Once GH-125413 is resolved, we'll be able to move
the `CopyReader` functionality into `ReadablePath.info` and eliminate
`ReadablePath._copy_reader`.
Remove _PyInterpreterState_GetConfigCopy() and
_PyInterpreterState_SetConfig() private functions. PEP 741 "Python
Configuration C API" added a better public C API: PyConfig_Get() and
PyConfig_Set().
Email generators using email.policy.default could incorrectly omit the
quote ('"') characters from a quoted-string during header refolding,
leading to invalid address headers and enabling header spoofing. This
change restores the quote characters on a bare-quoted-string as the
header is refolded, and escapes backslash and quote chars in the string.
There is a race condition between PyMem_SetAllocator() and
PyMem_RawMalloc()/PyMem_RawFree(). While PyMem_SetAllocator() write
is protected by a lock, PyMem_RawMalloc()/PyMem_RawFree() reads are
not protected by a lock. PyMem_RawMalloc()/PyMem_RawFree() can be
called with an old context and the new function pointer.
On a release build, it's not an issue since the context is not used.
On a debug build, the debug hooks use the context and so can crash.
In the free threading build, the per thread reference counting uses a
unique id for some objects to index into the local reference count
table. Use 0 instead of -1 to indicate that the id is not assigned. This
avoids bugs where zero-initialized heap type objects look like they have
a unique id assigned.
Implement set_name() with SetThreadDescription() and _get_name() with
GetThreadDescription(). If SetThreadDescription() or
GetThreadDescription() is not available in kernelbase.dll, delete the
method when the _thread module is imported.
Truncate the thread name to 32766 characters.
Co-authored-by: Eryk Sun <eryksun@gmail.com>
