frontmatter metadata is incorrectly folded

[blaenk]

So I found out about markdown-use-pandoc-style-yaml-metadata which is great. I use outline-minor-mode so that I can fold up all sections for example, but it ends up treating the line right before the end of the metadata block as a header.

[syohex]

outline-minor-mode uses outline-on-heading-p function for finding outline/markdown header. Its implementation is here. It used only regular expression for finding header line so that it mistakes to fold. In your case, the context, whether header line is in YAML header, should be considered for finding header line. Because it looks like outline header line but it is not actually header line.

(defun outline-on-heading-p (&optional invisible-ok)
  "Return t if point is on a (visible) heading line.
If INVISIBLE-OK is non-nil, an invisible heading line is ok too."
  (save-excursion
    (beginning-of-line)
    (and (bolp) (or invisible-ok (not (outline-invisible-p)))
     (looking-at outline-regexp))))

We cannot control its behaviour as we expected without overwriting function or advice feature.

[blaenk]

How about if we introduce an option to disable Setex headers (the ones underlined)? I only use ATX headers (the ones that go ## Header), and I always really see people using ATX headers. I'm not saying disable it outright, but since I never use them, I imagine it would help in a situation like this if I could personally disable them on my end.

[syohex]

How about if we introduce an option to disable Setex headers (the ones underlined)?

I disagree. Because it is markdown specification. And this is outline-mode issue. (I hope it should be customizable)

However you can change it by following configuration.

(defun my/markdown-mode-hook ()
  (setq-local outline-regexp "^\\(?:\\(#+\\)[ \t]+\\(.*?\\)[ \t]*\\(#*\\)\\)$"))
(add-hook 'markdown-mode-hook #'my/markdown-mode-hook)

[jrblevin]

markdown-mode has its own outline visibility cycling (section folding) functions which you should use rather than using outline-minor-mode functions directly. This is because, as you saw, the regular-expression-based approach of outline-minor-mode is too simple for Markdown documents. You can cycle visibility globally with Shift+Tab. Press it multiple times to see more or less.

The new commit (a646fea) adds code to un-hide text in the metadata block that outline-minor-mode mistakenly hides.