nsresult rv;
nsresult rv = NS_OK;
PRBool enumWriteEntryIfUnwritten(nsHashKey *aKey, void *aData, void* closure){  FILE *outStm = NS_STATIC_CAST(FILE*, closure);  if (!outStm)    return PR_FALSE;  nsCStringKey *stringKey = NS_STATIC_CAST(nsCStringKey*, aKey);  if (!stringKey)    return PR_FALSE;  HistoryEntry *entry = NS_STATIC_CAST(HistoryEntry*, aData);  if (!entry)    return PR_FALSE;  nsresult rv;  if (!entry->GetIsWritten())    rv = writeEntry(outStm, stringKey, entry);      return NS_SUCCEEDED(rv) ? PR_TRUE : PR_FALSE;}