title: Insertion Sort Doubly Link List Issues
body: <p>Sometimes when I run this code, a null reference exception occurs on the <code>Current.Next.Data = Hold.Data;</code>. </p>
  
  <pre><code>   private void InsertionSort()
      {
          for (Node FirstUnsorted = _Head.Next; FirstUnsorted != null; FirstUnsorted = FirstUnsorted.Next)
          {
              Node Hold = FirstUnsorted;
              Node Current;
  
              for (Current = FirstUnsorted.Prev; Current != null &amp;&amp; Current.Data.CompareTo(Hold.Data) &gt; 0; Current = Current.Prev)
                  Current.Next.Data = Current.Data;
  
              Current.Next.Data = Hold.Data;
          }
      }
  </code></pre>
  
  <p>I'm aware that you cannot reference the next node if the current node is equal to null, however I'm unable to determine a solution. <br /><br />How can I prevent this issue from occurring?</p>