title: Empty content picker does not return null when empty
body: <p>I have a content picker for a custom content type that needs to be placed in a specific zone on the page. It is working just fine with code like this (in Orchard 1.9.1):</p>
  
  <p>In placement.info:</p>
  
  <pre><code>  &lt;Match ContentType="MyContentType"&gt;
      &lt;Match DisplayType="Detail"&gt;
        &lt;Place Fields_ContentPicker-MyFieldName="MyZoneName:1"/&gt;
      &lt;/Match&gt;
    &lt;/Match&gt;
  </code></pre>
  
  <p>In the shape file (such as Content-MyContentType.Detail.cshtml):</p>
  
  <pre><code>@if (Model.MyZoneName != null)
  {
      &lt;div class="my-class"&gt;
          &lt;h3&gt;Some Title&lt;/h3&gt;
          @Zone(Model.MyZoneName)
      &lt;/div&gt;
  }
  </code></pre>
  
  <p>The problem is that if I have a content item with no content items in the content picker, it still displays "Some Title" because for some reason Model.MyZoneName is not coming back as null.</p>
  
  <p>I have tried countless things including these to no avail: </p>
  
  <ul>
  <li><code>@if (Model.ContentItem.MyPartName.MyFieldName.Count &gt; 1)</code> but there doesn't seem to be any available values that return the number of content items;</li>
  <li><code>@if (!String.IsNullOrWhiteSpace(Model.MyZoneName))</code> and <code>@if (!String.IsNullOrWhiteSpace(Model.ContentItem.MyPartName.MyFieldName.items[0]))</code> and others like that returned various error messages.</li>
  <li>etc.</li>
  </ul>
  
  <p>How can I get my check to return empty if there are no content items? It would be best if it was done with fix to the content picker module (assuming that's the issue), instead of trying to hack through .</p>