const PRUnichar *buffer; medium->GetUnicode(&buffer); aReturn.Assign(buffer); } else { aReturn.Truncate();
result = mStyleSheet->GetStyleRuleAt(aIndex, *getter_AddRefs(rule)); if (rule) { result = CallQueryInterface(rule, aReturn); mRulesAccessed = PR_TRUE; } else if (result == NS_ERROR_ILLEGAL_VALUE) { result = NS_OK; } }
DOMMediaListImpl::Item(PRUint32 aIndex, nsAWritableString& aReturn){  nsCOMPtr<nsISupports> tmp(dont_AddRef(ElementAt(aIndex)));  if (tmp) {    nsCOMPtr<nsIAtom> medium(do_QueryInterface(tmp));    NS_ENSURE_TRUE(medium, NS_ERROR_FAILURE);    const PRUnichar *buffer;    medium->GetUnicode(&buffer);    aReturn.Assign(buffer);  } else {    aReturn.Truncate();  }  return NS_OK;}