Copying property objects results in a TypeError. Steps to reproduce:
```
>>> import copy
>>> obj = property()
>>> copy.copy(obj)
````
This affects both shallow and deep copying.
My idea for a fix is to add property objects to the list of "atomic" objects in the copy module.
These already include types like functions and type objects.
I also added property objects to the unit tests test_copy_atomic and test_deepcopy_atomic. This is my first PR, and it's highly likely I've made some mistake, so please be kind :)
https://bugs.python.org/issue38293
Motivation for this PR (comment from @vstinner in bpo issue):
```
Warning seen o AMD64 Ubuntu Shared 3.x buildbot:
https://buildbot.python.org/all/#/builders/141/builds/2593
test_devnull_output (test.test_a=syncio.test_subprocess.SubprocessThreadedWatcherTests) ...
Warning -- threading_cleanup() failed to cleanup 1 threads (count: 1, dangling: 2)
```
The following implementation details for the new method are TBD:
1) Public vs private
2) Inclusion in `close()`
3) Name
4) Coroutine vs subroutine method
5) *timeout* parameter
If it's a private method, 3, 4, and 5 are significantly less important.
I started with the most minimal implementation that fixes the dangling threads without modifying the regression tests, which I think is particularly important. I typically try to avoid directly modifying existing tests as much as possible unless it's necessary to do so. However, I am open to changing any part of this.
https://bugs.python.org/issue38356
Although the underlying libffi issue remains open, adding these
checks have caused problems in third-party projects which are in
widespread use. See the issue for examples.
The corresponding tests have also been skipped.
nntplib.NNTP and nntplib.NNTP_SSL now raise a ValueError
if the given timeout for their constructor is zero to
prevent the creation of a non-blocking socket.
poplib.POP3 and poplib.POP3_SSL now raise a ValueError
if the given timeout for their constructor is zero to
prevent the creation of a non-blocking socket.
The fix changes copy_location() to require an extra node from which to extract the end location, and fixing all 5 call sites.
https://bugs.python.org/issue39235
* Add test cases for dataclasses.
* Add test for repr output of field.
* Add test for ValueError to be raised when both default and default_factory are passed.
Filename and line numbers are not needed when Py_REF_DEBUG are not
defined.
The static inline _Py_DECREF() function was introduced by
commit 2aaf0c1204.
imaplib.IMAP4 and imaplib.IMAP4_SSL now have an
optional *timeout* parameter for their constructors.
Also, the imaplib.IMAP4.open() method now has an optional *timeout* parameter
with this change. The overridden methods of imaplib.IMAP4_SSL and
imaplib.IMAP4_stream were applied to this change.
