if (bytesRead < (PRInt32)aCount) SetAtEOF(PR_TRUE);
NS_IMETHODIMP BasicStringImpl::Read(char* aBuf, PRUint32 aCount, PRUint32 *aReadCount)//----------------------------------------------------------------------------------------{  NS_PRECONDITION(aBuf != nsnull, "null ptr");  if (!aBuf)    return NS_ERROR_NULL_POINTER;  NS_PRECONDITION(aReadCount != nsnull, "null ptr");  if (!aReadCount)    return NS_ERROR_NULL_POINTER;  if (NS_FAILED(mLastResult))   return mLastResult;  PRInt32 bytesRead = read(aBuf, aCount);  if (NS_FAILED(mLastResult))  {    *aReadCount = 0;    return mLastResult;  }  *aReadCount = bytesRead;  return NS_OK;}