title: Vertical scroll bar appearing even when height is not set
body: <p>If you save the file below in html format, you will that a vertical scroll bar appears. Since the height for </p>
  
  <pre><code>&lt;div class="tabData" id="tab3data" style="visibility: visible;"&gt;
  </code></pre>
  
  <p>is not set, shouldn't it automatically expand to fit all the contents?</p>
  
  <pre><code>&lt;html dir="ltr" xmlns="http://www.w3.org/1999/xhtml"&gt;
  &lt;head&gt;
      &lt;style type="text/css"&gt;
          .tabData
          {
              width: 100%;
              background-color: Yellow;
              overflow: auto;
          }
      &lt;/style&gt;
  &lt;/head&gt;
  &lt;body&gt;
      &lt;div class="tabData"&gt;
          &lt;div style="height: 390px; background-color: Green;"&gt;
              &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt; &lt;br /&gt;
              &lt;/div&gt; 
          Hello
      &lt;/div&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p></p>