Piotr Caban (@piotr) commented about dlls/msvcrt/tests/file.c:
+#endif + + tempf = _tempnam(".","wne"); + file = fopen(tempf, "wb"); + + fprintf(file, "%s", "Hello World\n"); + ptrold = file->_ptr; + cntold = file->_cnt; + if (ptrold && cntold) + { + fprintf(file, "%s", "Hello"); + ok(ptrold + 5 == file->_ptr, "FILE _ptr incorrect"); + ok(cntold - 5 == file->_cnt, "FILE _cnt incorrect"); + ok(ptrold + cntold == file->_ptr + file->_cnt, "FILE _ptr or _cnt incorrect"); + ok(file->_ptr + file->_cnt == file->_base + file->_bufsiz, "FILE struct incorrect"); + ok(((file->_flag&_IOMYBUF) == _IOMYBUF), "file->_flag's _IOBUFFER_CRT incorrect"); It will probably also not work with PSDK headers, please use 0x40 instead.
-- https://gitlab.winehq.org/wine/wine/-/merge_requests/5752#note_72110