Extra indents being added for format selection with contentUnformatted tag

1 .Create a html document:

```

    <pre>
        stuff
    </pre>

```

2. Select from the start of the second line to the end of the file
3. Run format selection

**Bug**
Document becomes:

```

    <pre>
            stuff
        </pre>
```

If you continue running the command, more indents are added