Strikethrough text issue in commonmark_x mode about commonmark-hs

[jgm]

Apparently this is now being recognized as a definition list, when it wasn't before. The first ~ is being treated as the definition marker (it's an alternate to :, see the docs), which is why you get subscript rather than strikeout.

[jgm]

Simpler test:

% pandoc -f commonmark_x
foo
~~bar~~
^D
<dl>
<dt>foo</dt>
<dd>
<sub>bar</sub>~
</dd>
</dl>

[jgm]

I believe this change to commonmark-hs is at fault:
db528aa