title: Rowspan not working as expected
body: <p>I am trying to create a table layout as shown in below image:
  <a href="https://i.stack.imgur.com/croKZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/croKZ.png" alt="enter image description here"></a></p>
  
  <p>Below is my Html code:</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
      &lt;meta charset="UTF-8" /&gt;
      &lt;title&gt;Table sketch&lt;/title&gt;
      &lt;style&gt;
          table {
              table-layout: fixed;
              width: 20em;
          }
          td {
              width: 4em;
              height: 1.5em;
              text-align: center;
          }
      &lt;/style&gt;
  &lt;/head&gt;
  &lt;body&gt;
      &lt;table border="1"&gt;
          &lt;tr&gt;
              &lt;td colspan="4"&gt;&amp;nbsp;1&amp;nbsp;&lt;/td&gt;
          &lt;/tr&gt;
          &lt;tr&gt;
              &lt;td rowspan="2"&gt;&amp;nbsp;2&amp;nbsp;&lt;/td&gt;
              &lt;td rowspan="2"&gt;&amp;nbsp;3&amp;nbsp;&lt;/td&gt;
          &lt;/tr&gt;
          &lt;tr&gt;
              &lt;td colspan="2"&gt;&amp;nbsp;4&amp;nbsp;&lt;/td&gt;
          &lt;/tr&gt;
          &lt;tr&gt;
              &lt;td&gt;&amp;nbsp;5&amp;nbsp;&lt;/td&gt;&lt;td&gt;&amp;nbsp;6&amp;nbsp;&lt;/td&gt;
          &lt;/tr&gt;
          &lt;tr&gt;
              &lt;td colspan="4"&gt;&amp;nbsp;7&amp;nbsp;&lt;/td&gt;
          &lt;/tr&gt;
      &lt;/table&gt;
  &lt;/body&gt;
  </code></pre>
  
  <p></p>
  
  <p>But it generates below layout:</p>
  
  <p><a href="https://i.stack.imgur.com/bUo8u.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bUo8u.png" alt="enter image description here"></a></p>
  
  <p>When I change rowspan value from 2 to 3 for second row. It gives me right layout.</p>
  
  <pre><code>&lt;tr&gt;
      &lt;td rowspan="3"&gt;&amp;nbsp;2&amp;nbsp;&lt;/td&gt;
      &lt;td rowspan="3"&gt;&amp;nbsp;3&amp;nbsp;&lt;/td&gt;
  &lt;/tr&gt;
  </code></pre>
  
  <p>Here is a <a href="http://jsbin.com/hoqibuyuri/edit?html,output" rel="nofollow noreferrer">link</a> to jsbin.</p>
  
  <p>But why is first html code not working?
  Any help is much appreciated.</p>
  
  <p>Thanks.</p>