Akihiro Sagawa (@sgwaki) commented about dlls/kernel32/tests/path.c:
+ short_path[0] = 0; + short_len = GetShortPathNameW(tempdir, short_path, ARRAY_SIZE(short_path)); + ok(short_len, "GetShortPathNameW failed: %lu\n", GetLastError()); + + lstrcpyW(ext_short_path, prefix); + lstrcatW(ext_short_path, short_path); + lstrcatW(ext_short_path, name); + lstrcatW(ext_short_path, backslash); + lstrcatW(ext_short_path, name); + + SetLastError(0xdeadbeef); + long_len = GetLongPathNameW(ext_short_path, long_path, ARRAY_SIZE(long_path)); + todo_wine + { + ok(long_len > 0, "GetLongPathNameW failed: %ld\n", GetLastError()); + ok(!wcsncmp(long_path, prefix, 4), "Expected extended prefix in output, got %s\n", wine_dbgstr_w(long_path)); It would be good to test the whole path to determine whether it is a long path name or a short path name.
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/10192#note_133721