RtlStringCbCatNW - NtDoc

#ifndef _NTSTRSAFE_H_INCLUDED_
#ifndef NTSTRSAFE_LIB_IMPL
#ifndef NTSTRSAFE_NO_CB_FUNCTIONS

NTSTRSAFEDDI
    RtlStringCbCatNW(
            _Inout_updates_bytes_(cbDest) _Always_(_Post_z_) NTSTRSAFE_PWSTR pszDest,
            _In_ size_t cbDest,
            _In_reads_bytes_(cbToAppend) STRSAFE_PCNZWCH pszSrc,
            _In_ size_t cbToAppend)
{
    NTSTATUS status;
    size_t cchDest = cbDest / sizeof(wchar_t);
    size_t cchDestLength;

    status = RtlStringValidateDestAndLengthW(pszDest,
            cchDest,
            &cchDestLength,
            NTSTRSAFE_MAX_CCH);

    if (NT_SUCCESS(status))
    {
        size_t cchToAppend = cbToAppend / sizeof(wchar_t);

        if (cchToAppend > NTSTRSAFE_MAX_LENGTH)
        {
            status = STATUS_INVALID_PARAMETER;
        }
        else
        {
            status = RtlStringCopyWorkerW(pszDest + cchDestLength,
                    cchDest - cchDestLength,
                    NULL,
                    pszSrc,
                    cchToAppend);
        }
    }

    return status;
}

#endif
#endif
#endif
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