title: SKProductRequest doesn't fail without connection
body: <p>I'd would like to handle the case in which in-app purchase products are requested without an internet connection.</p>
  
  <p>When testing this case both in the simulator and a device (by turning off the wi-fi), instead of receiving a call to <code>request:didFailWithError:</code>, I receive a call <code>productsRequest:didReceiveResponse:</code> with an empty products array and then to <code>requestDidFinish:</code>.</p>
  
  <p>Is this the expected behavior? If so, how can I know if the request failed due to a connection issue? If not, what might be wrong?</p>
  
  <p>In case it helps, this is how I request the products:</p>
  
  <pre><code>- (void) requestProducts:(NSSet*)identifiers
  {
      _productsRequest = [[SKProductsRequest alloc] initWithProductIdentifiers:identifiers];
      _productsRequest.delegate = self;
      [_productsRequest start];
  }
  </code></pre>
  
  <p>I'm using iOS 6.</p>