prov->GetFile(fileData->property, &fileData->persistent, &(fileData->file) ); if (fileData->file)
rv = prov->GetFile(fileData->property, &fileData->persistent, &(fileData->file) ); if (NS_SUCCEEDED(rv) && fileData->file)
static PRBool FindProviderFile(nsISupports* aElement, void *aData){  nsCOMPtr<nsIDirectoryServiceProvider> prov = do_QueryInterface(aElement);  if (!prov)    return PR_FALSE;  FileData* fileData = (FileData*)aData;  prov->GetFile(fileData->property, &fileData->persistent, &(fileData->file) );  if (fileData->file)    return PR_FALSE;  return PR_TRUE;}