Bold formatting on partial link text splits single <a> into multiple anchor elements

[Dennis273]

Description

When selecting part of the text inside a hyperlink and applying bold formatting, the single <a> element is split into multiple <a> elements with the same href.

Steps to Reproduce

1. Open the RoosterJS demo page
2. Type or paste a URL (e.g., <http://www.google.com>) and let it auto-link
3. Select part of the link text (e.g., select "google")
4. Click the Bold button

Expected

<a href="<http://www.google.com>" title="<http://www.google.com>">
  <http://www>.<b>google</b>.com
</a>

Actual

<a href="<http://www.google.com>" title="<http://www.google.com>"><http://www.></a>
<b><a href="<http://www.google.com>" title="<http://www.google.com>">google</a></b>
<a href="<http://www.google.com>" title="<http://www.google.com>">.com</a>

One anchor is split into three. This also applies to other inline formats like italic, underline, etc.