[Bug 54607] New: user32:clipboard - test_string_data() fails on Windows in mixed locales

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54607

Bug ID: 54607
           Summary: user32:clipboard - test_string_data() fails on Windows
                    in mixed locales
           Product: Wine
           Version: unspecified
          Hardware: x86-64
                OS: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: user32
          Assignee: [e-mail]
          Reporter: [e-mail]

user32:clipboard - test_string_data() fails on Windows in mixed locales:

clipboard.c:2351: Test failed: 7: wrong size 2 / 3
clipboard.c:2352: Test failed: 7: wrong data "a\x00", expected "\x83\xbf\x00"
025c:clipboard: 7 tests executed (0 marked as todo, 0 as flaky, 2 failures), 0
skipped.
clipboard.c:231: 2 failures in child process
clipboard.c:2351: Test failed: 8: wrong size 3 / 5
clipboard.c:2352: Test failed: 8: wrong data "a\xdf\x00", expected
"\x83\xbf\x83\xc0\x00"
1d98:clipboard: 7 tests executed (0 marked as todo, 0 as flaky, 2 failures), 0
skipped.
clipboard.c:231: 2 failures in child process
clipboard.c:2351: Test failed: 9: wrong size 3 / 5
clipboard.c:2352: Test failed: 9: wrong data "a\xdf\x00", expected
"\x83\xbf\x83\xc0\x00"
1e40:clipboard: 7 tests executed (0 marked as todo, 0 as flaky, 2 failures), 0
skipped.
clipboard.c:231: 2 failures in child process
clipboard.c:2351: Test failed: 10: wrong size 4 / 7
clipboard.c:2352: Test failed: 10: wrong data "a\xdf?\x00", expected
"\x83\xbf\x83\xc0\x83\xc1\x00"
0234:clipboard: 7 tests executed (0 marked as todo, 0 as flaky, 2 failures), 0
skipped.
clipboard.c:231: 2 failures in child process
clipboard.c:2351: Test failed: 11: wrong size 4 / 7
clipboard.c:2352: Test failed: 11: wrong data "a\xdf?\x00", expected
"\x83\xbf\x83\xc0\x83\xc1\x00"
0578:clipboard: 7 tests executed (0 marked as todo, 0 as flaky, 2 failures), 0
skipped.
clipboard.c:231: 2 failures in child process

See https://test.winehq.org/data/patterns.html#user32:clipboard

A bisect shows that this failure started with the commit below:

commit 605ecafa67a4e034328b69396581e2f9b60d7af3
Author:     François Gouget 
AuthorDate: Wed Dec 21 18:48:29 2022 +0100

user32: Fix a SetClipboardData() buffer overflow.

Wine would append a correctly aligned NUL Unicode character to
    terminate the string but overflow the buffer by one byte for odd-sized
    strings.
    Windows instead overwrites the last two buffer bytes with a NUL Unicode
    character which ends up being misaligned for odd-sized strings.
    The clipboard data has a size field anyway so match the Windows
    behavior.
    Tweak the tests to show that SetClipboardData() can overwrite half of
    the Unicode string's last character.