Steps to reproduce:
1. Insert two lists
<ol>
    <li>test1</li>
</ol>
<ol>
    <li>test2</li>
</ol>
2. Copy the first list
3. Insert one more list item in the second list and paste the first list
Expected:
<ol>
    <li>test1</li>
</ol>
<ol>
    <li>test2</li>
    <li>test1</li>
</ol>
Actual:
<ol>
    <li>test1</li>
</ol>
<ol>
    <li>test2</li>
    <li>
    <ol>
        <li>test1</li>
    </ol>
    </li>
</ol>