else
else if (!mDone)
NS_IMETHODIMP nsMsgThreadEnumerator::Next(void){	nsresult rv;	if (mCurKey == nsMsgKey_None)	{		rv = mThread->GetChildHdrAt(0, &mResultHdr);		mChildIndex = 1;	}	else	{		rv  = mThread->GetChildHdrAt(mChildIndex++, &mResultHdr);	}	if (!mResultHdr) 	{        mDone = PR_TRUE;		return NS_RDF_CURSOR_EMPTY;    }    if (NS_FAILED(rv)) 	{        mDone = PR_TRUE;        return rv;    }	return rv;}