Line break incorrectly inserted in formatted lines

[luiscubal]

Steps to reproduce the problem (provide example Markdown if applicable):

Hello  
**Bar**
Foo

(with two spaces at the end of the first line, none at the end of the second line)

Expected behavior:

<p>Hello<br />
<strong>World</strong>
Next line</p>

Actual behavior:

<p>Hello<br />
<strong>World</strong><br />
Next line</p>

Note: if the line is **World**x instead of **World**, then no line break is inserted.
Tested in commonmark 0.27.0.