Corrupted code block after HTML block comment

[step-]

Example https://spec.commonmark.org/0.30/#example-134
Running md2html with just the example and no other text included meets the spec. However, when I add an HTML block before the example the test result changes unexpectedly and fails the spec.
Failing test subject:

<!-- x -->
    ```
    aaa
    ```

Expected output:

<!-- x -->
<pre><code>```
aaa
```
</code></pre>

Actual output (fail):

<!-- x -->
<pre><code>aaa
```
</code></pre>

---

Here's another example of the same problem. This time the HTML comment spans two lines. As in the first example, md2html is missing some text in the rendered code block.

<!-- x
-->
    ```
    aaa
    ```

Expected output:

<!-- x
-->
<pre><code>```
aaa
```
</code></pre>

Actual output (fail):

<!-- x
-->
<pre><code>aaa
```
</code></pre>

[N-R-K]

Indented code blocks need to be separated by black lines: https://spec.commonmark.org/0.30/#indented-code-blocks

[step-]

Indented code blocks need to be separated by black lines: https://spec.commonmark.org/0.30/#indented-code-blocks

I read that section differently. It says that there must be a blank line before the block to interrupt a preceding paragraph. The failing example concerns a type 2 HTML block, https://spec.commonmark.org/0.30/#html-blocks, before an indented code block. In the failing example, the HTML block is properly ended. Then comes an indented code block, which is rendered incorrectly. Running the failing example under cmark yields the reference output shown in my report.

[step-]

edit: this is now issue #201

As a follow-up to @N-R-K's comment I verified md2html vs cmark for the following failing test subject:

start
    ```
    aaa
    ```

According to the spec linked above, the whole subject constitutes a paragraph that starts with "start" and ends with the second "```". If there was a blank line after the start line then the subject would consists of a one-line paragraph followed by a code block. Below we can see that cmark renders the test subject as a whole paragraph, stripping white space before lines 2, 3 and 4, which then amount to a code span.

cmark

<p>p
<code>aaa</code></p>

Below we can see that md2html renders the test subject incorrectly, much the same way it rendered the original subject above incorrectly:

md2html:

<p>p</p>
<pre><code>aaa
```
</code></pre>

Conclusion: non-conformance is broader than I originally observed.

I spent time tracing md4c.c and I'm pretty confident that the problem originates in the parser code and not in md2html application code.