title: OrderByDescending not working properly in Linq
body: <p>I am using Linq and have the following code in C#:</p>
  
  <pre><code>leaves = GetAnnualLeaves();
  otherleaves = GetOtherLeaves();
  leaves.AddRange(otherleaves);
  leaves.OrderByDescending(e =&gt; e.StartDate);
  </code></pre>
  
  <p>Basically I am trying to display list of annual and other leaves and I want to display them in DESCENDING order. Problem is it always shows "Other Leaves" at the end of "Annual Leaves" no matter what. So basically it displays like this:</p>
  
  <pre><code>2013-06-29 Annual
  2012-01-01 Annual
  2011-05-02 Annual
  2013-05-01 Other
  </code></pre>
  
  <p>When in fact it should display like this:</p>
  
  <pre><code>2013-06-29 Annual
  2013-05-01 Other
  2012-01-01 Annual
  2011-05-02 Annual
  </code></pre>
  
  <p>Any idea why order by descending is not working?</p>
  
  <p><strong>EDIT</strong> </p>
  
  <p>I am getting casting error when I use CONCAT.  </p>
  
  <p>Both "Annual" and "Other" leaves are of same type but when I do</p>
  
  <pre><code>leaves = leaves.Concat(otherleaves) 
  </code></pre>
  
  <p>then the project doesn't compile and gives error</p>
  
  <pre><code>Cannot implicitly convert type System.Collections.Generic.IEnumerable&lt;MyEntity&gt; to System.Collections.Generic.List&lt;MyEntity&gt;
  </code></pre>
  
  <p>And if I do type cast:</p>
  
  <pre><code>leaves = (List&lt;MyEntity&gt;)leaves.Concat(otherleaves)
  </code></pre>
  
  <p>then I get runtime error.</p>