unexpected back tick (md2html vs cmark)

[step-]

A list item combining spaced back ticks and hard break is parsed incorrectly. To reproduce:

cmark --version
cmark 0.31.1 - CommonMark converter
(C) 2014-2016 John MacFarlane
md2html --version
0.5.2

---

cat /tmp/t.md (with two spaces after BR)

* `
  code
  ` BR  
  continuation

---

md2html --xhtml /tmp/t.md (note the unexpected closing back tick)

<ul>
<li><code>code</code>
` BR<br />
continuation</li>
</ul>

---

cmark /tmp/t.md (no closing back tick)

<ul>
<li><code>code</code> BR<br />
continuation</li>
</ul>