nsresult rv;
if (res == NULL) return NS_ERROR_INVALID_POINTER; if (NS_FAILED(SecurePrefCheck(pref))) return NS_ERROR_FAILURE;
NS_IMETHODIMP nsPref::PrefIsLocked(const char *aPrefName, PRBool *_retval){  nsresult rv;  nsCOMPtr<nsIPrefBranch> prefBranch = do_QueryInterface(mPrefService, &rv);  if (NS_SUCCEEDED(rv))    rv = prefBranch->PrefIsLocked(aPrefName, _retval);  return rv;}