c
SSIZE_T ConvertUtf8NToWChar(const char* str, size_t len, WCHAR* wstr, size_t wlen)
{
    // ... (existing code)

    WINPR_ASSERT(str);  // Keep this assertion for the destination buffer
    WINPR_ASSERT(len == 0 || str != NULL); // Assert src is not NULL if len > 0
    size_t ilen = (str == NULL) ? 0 : strnlen(str, len); // Safeguard against NULL str
    // ... (rest of the function)
}
