pandoc/test/command/5650.md

% pandoc --id-prefix foo
```haskell
a
b
```
^D
<div class="sourceCode" id="foocb1"><pre class="sourceCode haskell"><code class="sourceCode haskell"><span id="foocb1-1"><a href="#foocb1-1"></a>a</span>
<span id="foocb1-2"><a href="#foocb1-2"></a>b</span></code></pre></div>

% pandoc --id-prefix foo
``` {.haskell #bar}
a
b
```
^D
<div class="sourceCode" id="foobar"><pre class="sourceCode haskell"><code class="sourceCode haskell"><span id="foobar-1"><a href="#foobar-1"></a>a</span>
<span id="foobar-2"><a href="#foobar-2"></a>b</span></code></pre></div>