Unexpected discrepancy between renders of code-blocks and code-span #752
Description
Hi, the following discrepancy was detected while investigating jekyll/jekyll#8990
For context, Jekyll sets config["syntax_highlighter_opts"]["default_lang"] ||= "plaintext" prior to passing config onto kramdown.
With this set up, when Jekyll renders the following snippet:
This is a Ruby code fragment `x = Class.new`{:.language-ruby}
```
def what?
42
end
```
{: .language-ruby}
into:
<p>This is a Ruby code fragment <code class="language-plaintext highlighter-rouge"><span class="n">x</span> <span class="o">=</span> <span class="no">Class</span><span class="p">.</span><span class="nf">new</span></code></p>
<div class="language-ruby highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="k">def</span> <span class="nf">what?</span>
<span class="mi">42</span>
<span class="k">end</span>
</code></pre></div></div>
Note how code-span gets language-plaintext assigned while the code-block gets language-ruby.
I'm not saying this is a bug with kramdown. But would like to get your opinion on the situation.