wrong type for wintypes.BYTE

[techtonik]

BPO	16376
Nosy	@amauryfa, @abalkin, @meadori
Files	Issue16376.diff: Change BYTE definition fron c_byte to c_ubyte

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2012-10-31.17:02:55.557>
labels = ['ctypes', 'type-bug', '3.9', '3.10', '3.11']
title = 'wrong type for wintypes.BYTE'
updated_at = <Date 2021-06-17.10:29:15.374>
user = 'https://bugs.python.org/techtonik'

bugs.python.org fields:

activity = <Date 2021-06-17.10:29:15.374>
actor = 'iritkatriel'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['ctypes']
creation = <Date 2012-10-31.17:02:55.557>
creator = 'techtonik'
dependencies = []
files = ['35940']
hgrepos = []
issue_num = 16376
keywords = ['patch']
message_count = 2.0
messages = ['174331', '222935']
nosy_count = 4.0
nosy_names = ['amaury.forgeotdarc', 'belopolsky', 'techtonik', 'meador.inge']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue16376'
versions = ['Python 3.9', 'Python 3.10', 'Python 3.11']

Linked PRs

• gh-60580: Fix a wrong type of ctypes.wintypes.BYTE #97579

[techtonik]

Windows BYTE type is unsigned char, but ctypes defines it as signed.

{{{
BYTE	
A byte (8 bits).
This type is declared in WinDef.h as follows:
typedef unsigned char BYTE;
typedef unsigned char BYTE;
}}}
http://msdn.microsoft.com/en-us/library/windows/desktop/aa383751(v=vs.85).aspx

http://hg.python.org/cpython/file/e5f39546989f/Lib/ctypes/wintypes.py#l4

[BreamoreBoy]

All cbytes tests passed after the change was made but I've no idea as to the impact of this.

[elibroftw]

This bug can cause people to make grave mistakes when using WIndows APIs. Im assuming this is a simple fix too.
Just because "cbytes" tests pass does not mean practical tests will pass. Take for example
https://stackoverflow.com/a/6156606/7732434

Run this code as shown and then run the code with types ctypes.c_ubyte instead of wintypes.BYTE. You can see that the latter works as expected according to Microsofts own specs as seen in the link below.

https://learn.microsoft.com/en-us/windows/win32/api/winbase/ns-winbase-system_power_status

This would be a wintypes.BYTE test that would not pass

[arhadthedev]

Fixed by gh-97579; no backporting is planned.