[Bug 58359] New: IsTextUnicode returns incorrect result on IS_TEXT_UNICODE_ILLEGAL_CHARS

[WineHQ Bugzilla]

http://bugs.winehq.org/show_bug.cgi?id=58359

Bug ID: 58359
           Summary: IsTextUnicode returns incorrect result on
                    IS_TEXT_UNICODE_ILLEGAL_CHARS
           Product: Wine
           Version: 10.8
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: advapi32
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

When running following sample it prints ok in wine, but it should be invalid
string

```
#include <windows.h>

void testUni(){
    int isUni = IS_TEXT_UNICODE_ILLEGAL_CHARS;
    wchar_t buf[2];
    buf[0] = 0xFFFF;
    buf[1] =0;
    IsTextUnicode((void *)buf, 4, &isUni);
    if (isUni & IS_TEXT_UNICODE_ILLEGAL_CHARS) {
        printf("invalid string");
    } else {
        printf("ok");
    }
}

```