The truncate() method of io.BufferedReader() should raise
UnsupportedOperation when it is called on a read-only
io.BufferedReader() instance.
https://bugs.python.org/issue35950
Automerge-Triggered-By: @methane
The bulk of this patch was generated automatically with:
for name in \
PyObject_Vectorcall \
Py_TPFLAGS_HAVE_VECTORCALL \
PyObject_VectorcallMethod \
PyVectorcall_Function \
PyObject_CallOneArg \
PyObject_CallMethodNoArgs \
PyObject_CallMethodOneArg \
;
do
echo $name
git grep -lwz _$name | xargs -0 sed -i "s/\b_$name\b/$name/g"
done
old=_PyObject_FastCallDict
new=PyObject_VectorcallDict
git grep -lwz $old | xargs -0 sed -i "s/\b$old\b/$new/g"
and then cleaned up:
- Revert changes to in docs & news
- Revert changes to backcompat defines in headers
- Nudge misaligned comments
When called on a closed object, readinto() segfaults on account
of a write to a freed buffer:
==220553== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==220553== Access not within mapped region at address 0x2A
==220553== at 0x48408A0: memmove (vg_replace_strmem.c:1272)
==220553== by 0x58DB0C: _buffered_readinto_generic (bufferedio.c:972)
==220553== by 0x58DCBA: _io__Buffered_readinto_impl (bufferedio.c:1053)
==220553== by 0x58DCBA: _io__Buffered_readinto (bufferedio.c.h:253)
Reproducer:
reader = open ("/dev/zero", "rb")
_void = reader.read (42)
reader.close ()
reader.readinto (bytearray (42)) ### BANG!
The problem exists since 2012 when commit dc469454ec added code
to free the read buffer on close().
Signed-off-by: Philipp Gesang <philipp.gesang@intra2net.com>
It is now allowed to add new fields at the end of the PyTypeObject struct without having to allocate a dedicated compatibility flag in tp_flags.
This will reduce the risk of running out of bits in the 32-bit tp_flags value.
* Maintain a list of BufferedWriter objects. Flush them on exit.
In Python 3, the buffer and the underlying file object are separate
and so the order in which objects are finalized matters. This is
unlike Python 2 where the file and buffer were a single object and
finalization was done for both at the same time. In Python 3, if
the file is finalized and closed before the buffer then the data in
the buffer is lost.
This change adds a doubly linked list of open file buffers. An atexit
hook ensures they are flushed before proceeding with interpreter
shutdown. This is addition does not remove the need to properly close
files as there are other reasons why buffered data could get lost during
finalization.
Initial patch by Armin Rigo.
* Use weakref.WeakSet instead of WeakKeyDictionary.
* Simplify buffered double-linked list types.
* In _flush_all_writers(), suppress errors from flush().
* Remove NEWS entry, use blurb.
* Take more care when flushing file buffers from atexit.
The previous implementation was not careful enough to avoid
causing issues in multi-threaded cases. Check for buf->ok
and buf->finalizing before actually doing the flush. Also,
increase the refcnt to ensure the object does not disappear.
