Replace "#if WITH_THREAD" with "#ifdef WITH_THREAD".

Issue #27278. It should fix a conversion warning.

In practice, the Linux kernel doesn't return more than 32 MB per call to the
getrandom() syscall.

Patch by John Hagen.

by Jelle Zijlstra.

by Jelle Zijlstra.

managed by a contextlib.ExitStack() and one of the exit stack
generators catches and raises it in a chain, do not re-raise the
original exception when exiting, let the new chained one through.
This avoids the PEP 479 bug described in issue25782.

managed by a contextlib.ExitStack() and one of the exit stack
generators catches and raises it in a chain, do not re-raise the
original exception when exiting, let the new chained one through.
This avoids the PEP 479 bug described in issue25782.

* Add the process identifier to the warning message
* Add also a comment to explain the issue

Casting Py_ssize_t to Py_ssize_t is useless.

Issue #27278: Fix os.urandom() implementation using getrandom() on Linux.
Truncate size to INT_MAX and loop until we collected enough random bytes,
instead of casting a directly Py_ssize_t to int.

Initial patch by Alex LordThorsen.