[Markdown] Dash-separated long list items rendered as sublist

[kdeldycke]

Here is a Markdown file with a list of very long items:

❯ cat ./dash-separated-link-list.md
- [Link 1](#link-1) - Description of line 1.
- [Link 2](#link-2) - A very long description for the second link in the list. That description is more than 80 characters wide.
- [This is a very long title, pointing to an awesome article on incredible stuff we're not used to see everyday](#link-3) - Line #3's description.
- [Link number three](#this-is-a-very-long-url-that-is-pointing-to-a-really-really-great-website) - Fourth description.

Which renders into a clean list of four items:

• Link 1 - Description of line 1.
• Link 2 - A very long description for the second link in the list. That description is more than 80 characters wide.
• This is a very long title, pointing to an awesome article on incredible stuff we're not used to see everyday - Line pandoc installation on ubuntu completely missing s5 folder - /s5/default/s5-core.css: openFile: does not exist  #3's description.
• Link number three - Fourth description.

Now I want to clean this file and have pandoc automatically wraps long lines. Here is the CLI I run:

❯ pandoc ./dash-separated-link-list.md --to=gfm
  - [Link 1](#link-1) - Description of line 1.
  - [Link 2](#link-2) - A very long description for the second link in
    the list. That description is more than 80 characters wide.
  - [This is a very long title, pointing to an awesome article on
    incredible stuff we’re not used to see everyday](#link-3) - Line
    \#3’s description.
  - [Link number
    three](#this-is-a-very-long-url-that-is-pointing-to-a-really-really-great-website)
    - Fourth description.

Which renders to:

• Link 1 - Description of line 1.
• Link 2 - A very long description for the second link in the list. That description is more than 80 characters wide.
• This is a very long title, pointing to an awesome article on incredible stuff we’re not used to see everyday - Line pandoc installation on ubuntu completely missing s5 folder - /s5/default/s5-core.css: openFile: does not exist  #3’s description.
• Link number three
  • Fourth description.

You can see how the fourth description is rendered as a sub-list because of the dash? I think this is a bug.

What's interesting in this case is that other variants of Markdown seems to account for this edge-case and keep the dash in the previous line to prevent accidental rendering of sublists:

❯ pandoc ./dash-separated-link-list.md --to=markdown_github
[WARNING] Deprecated: markdown_github. Use gfm instead.
-   [Link 1](#link-1) - Description of line 1.
-   [Link 2](#link-2) - A very long description for the second link in
    the list. That description is more than 80 characters wide.
-   [This is a very long title, pointing to an awesome article on
    incredible stuff we’re not used to see everyday](#link-3) - Line
    \#3’s description.
-   [Link number
    three](#this-is-a-very-long-url-that-is-pointing-to-a-really-really-great-website) -
    Fourth description.

❯ pandoc ./dash-separated-link-list.md --to=markdown_mmd
-   [Link 1](#link-1) - Description of line 1.
-   [Link 2](#link-2) - A very long description for the second link in
    the list. That description is more than 80 characters wide.
-   [This is a very long title, pointing to an awesome article on
    incredible stuff we’re not used to see everyday](#link-3) - Line
    \#3’s description.
-   [Link number
    three](#this-is-a-very-long-url-that-is-pointing-to-a-really-really-great-website) -
    Fourth description.

❯ pandoc ./dash-separated-link-list.md --to=markdown_strict
-   [Link 1](#link-1) - Description of line 1.
-   [Link 2](#link-2) - A very long description for the second link in
    the list. That description is more than 80 characters wide.
-   [This is a very long title, pointing to an awesome article on
    incredible stuff we’re not used to see everyday](#link-3) - Line
    \#3’s description.
-   [Link number
    three](#this-is-a-very-long-url-that-is-pointing-to-a-really-really-great-website) -
    Fourth description.

For the record, here is my version of pandoc, straight out of brew on macOS Catalina:

❯ pandoc --version
pandoc 2.9.2.1
Compiled with pandoc-types 1.20, texmath 0.12.0.1, skylighting 0.8.3.2

[jgm]

For gfm we use libcmark's renderer, which in this respect is less sophisticated than the native pandoc renderers. (Of course I could do something about this, since I'm also the maintainer of libcmark, but it would have to be fixed there: commonmark/cmark on GitHub. You can report this there if you like.)

[kdeldycke]

Thanks @jgm for the tip. I just reproduced the bug with the standalone cmark CLI and created a bug report at commonmark/cmark#347 .

[kdeldycke]

BTW @jgm, what do you think of @DavidAnson workaround at DavidAnson/markdownlint#302 (comment) of using link references?

[jgm]

I'll close here, since it's really an upstream issue.
Yes, using link references can help in particular cases.

[kdeldycke]

Fair enough! Thanks @jgm for the feedback! :)