title: TabControl.VerticalAlignment = Stretch doesn't do anything
body: <p>I am trying to make a TabControl to auto resize according to the its outer space(it's in a StackPanel):</p>
  
  <pre><code>&lt;Window x:Class="Window1"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Height="100"&gt;
      &lt;Grid&gt;
          &lt;StackPanel&gt;
              &lt;TabControl 
                  BorderBrush="Red" 
                  BorderThickness="2" 
                  VerticalAlignment="Stretch" 
                  VerticalContentAlignment="Stretch"&gt;
  
                  &lt;TabItem Header="Tab1"/&gt;
                  &lt;TabItem Header="Tab2"/&gt;
              &lt;/TabControl&gt;
          &lt;/StackPanel&gt;
      &lt;/Grid&gt;
  &lt;/Window&gt;
  </code></pre>
  
  <p>The snippet above produces the following window, whilst I want the red border to reach the bottom of the window:  </p>
  
  <p><img src="https://farm5.static.flickr.com/4058/4219296235_25ab9acabf_o.png" alt="alt text"></p>