[issue30353] ctypes: pass by value for structs broken on Cygwin/MinGW 64-bit

[Erik Bray]

Erik Bray added the comment:

Thanks for pointing that out.  Indeed it's the same symptom, but slightly different cause.  libffi has different implementations of its calling routines for different architectures/platforms depending on the machine architecture and calling conventions used.  So this case is probably buggy for the arm64 implementation as well, as in #29804.

Off the top of my head I don't know a reliable way to check for this case, but this fix would work around the arm64 issue as well if I could check for that architecture easily at compile time.

----------

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue30353>
_______________________________________