Summary splitter (more comment) at end of post content (file or subtree) causes error

[zzamboni]

First of all, I'd like to say THANK YOU for ox-hugo - it has revolutionized how I maintain my Hugo-powered website using org-mode.

I have found a strange behavior in what should be a very uncommon corner case, but here it is anyway: if a post contains a <!--more--> tag as its last line, upon export I get the prompt Buffer test.md modified; kill anyway?, and then no matter what I respond, I get the error markdown-syntax-propertize-comments: Wrong type argument: integer-or-marker-p, nil, and the file is not exported.

Very easy workaround: adding some text after the <!--more--> line, even if it's just a \nbsp, then the export works fine (this is why I think this is an uncommon corner case, in regular use this shouldn't happen).

Here's a short file which reproduces the problem:

#+hugo_base_dir: ../

* DONE Test post
CLOSED: [2018-04-05 Thu 14:33]
:PROPERTIES:
:EXPORT_FILE_NAME: test
:END:

Here is some test.

@@html:<!--more-->@@

In case you are curious: I came across this because I have a short page in which I want to have the <!--more--> tag to influence the generation of the post summary by Hugo (I cannot use the :summary custom front matter because in this case I want the summary to include some HTML generated by a custom Hugo shortcode, which would otherwise get stripped out).

Versions: Emacs 25.3.2, Org mode 9.1.8, ox-hugo 20180403.1111 from MELPA

[kaushalmodi]

First of all, I'd like to say THANK YOU for ox-hugo - it has revolutionized how I maintain my Hugo-powered website using org-mode.

Thanks!

no matter what I respond, I get the error markdown-syntax-propertize-comments: Wrong type argument: integer-or-marker-p, nil, and the file is not exported.

That sounds like a bug. Can you do M-x toggle-debug-on-error, then recreate that error. That should throw a backtrace, paste that here. Thanks.

I'll also try to reproduce the problem locally, but the backtrace will immensely help.

[kaushalmodi]

And to the question:

How to insert <!--more--> tag in a post?

You can simply do:

#+hugo: more

[zzamboni]

Thanks for the quick response! Here's the backtrace:
https://gist.github.com/zzamboni/d4cab2c2d26aa981a9094d60a0c0551e

Thanks for the tip about the more tag! Much cleaner that way. It still triggers the same error though :)

[kaushalmodi]

OK, I was able to reproduce this issue even with:

*** Summary Splitter at EOF                                             :eof:
:PROPERTIES:
:EXPORT_FILE_NAME: summary-splitter-at-eof
:END:
Here is the summary.
#+hugo: more

I'll take a look by the end of today.

[kaushalmodi]

Hmm, it's definitely a bug.. but looks like a markdown-mode bug based on this:

Debugger entered--Lisp error: (wrong-type-argument integer-or-marker-p nil)
  remove-text-properties(nil 269 (markdown-tilde-fence-begin nil markdown-tilde-fence-end nil markdown-fenced-code nil markdown-yaml-metadata-begin nil markdown-yaml-metadata-end nil markdown-yaml-metadata-section nil markdown-gfm-block-begin nil markdown-gfm-block-end nil markdown-gfm-code nil markdown-list-item nil markdown-pre nil markdown-blockquote nil markdown-hr nil markdown-comment nil markdown-heading nil markdown-heading-1-setext nil markdown-heading-2-setext nil markdown-heading-1-atx nil markdown-heading-2-atx nil markdown-heading-3-atx nil markdown-heading-4-atx nil markdown-heading-5-atx nil markdown-heading-6-atx nil markdown-metadata-key nil markdown-metadata-value nil markdown-metadata-markup nil))
  markdown-syntax-propertize-comments(263 270)
  markdown-syntax-propertize-comments(258 270)
  markdown-syntax-propertize(258 270)
  markdown-font-lock-extend-region-function(269 270 0)
  run-hook-with-args(markdown-font-lock-extend-region-function 269 270 0)
  jit-lock-after-change(269 270 0)
  #f(compiled-function (&optional called-interactively) "Save the current buffer in its visited file, if it has been modified.\n\nThe hooks `write-contents-functions', `local-write-file-hooks'\nand `write-file-functions' get a chance to do the job of saving;\nif they do not, then the buffer is saved in the visited file in\nthe usual way.\n\nBefore and after saving the buffer, this function runs\n`before-save-hook' and `after-save-hook', respectively." (interactive '(called-interactively)) #<bytecode 0x290dc7>)(nil)
  apply(#f(compiled-function (&optional called-interactively) "Save the current buffer in its visited file, if it has been modified.\n\nThe hooks `write-contents-functions', `local-write-file-hooks'\nand `write-file-functions' get a chance to do the job of saving;\nif they do not, then the buffer is saved in the visited file in\nthe usual way.\n\nBefore and after saving the buffer, this function runs\n`before-save-hook' and `after-save-hook', respectively." (interactive '(called-interactively)) #<bytecode 0x290dc7>) nil)
  basic-save-buffer(nil)
  save-buffer()
  write-file("/home/kmodi/stow/pub_dotfiles/emacs/dot-emacs.d/elisp/ox-hugo/test/site/content/posts/summary-splitter-at-eof.md")
  org-export-to-file(hugo "/home/kmodi/stow/pub_dotfiles/emacs/dot-emacs.d/elisp/ox-hugo/test/site/content/posts/summary-splitter-at-eof.md" nil (headline (:raw-value "Summary Splitter at EOF" :begin 63695 :end 63967 :pre-blank 0 :contents-begin 63773 :contents-end 63967 :level 3 :priority nil :tags (#("eof" 0 3 (keymap (keymap (mouse-3 . org-find-file-at-mouse) (mouse-2 . org-open-at-mouse)) mouse-face highlight face (org-tag org-level-3) wrap-prefix #("*** " 0 4 (face org-indent)) line-prefix "" fontified t))) :todo-keyword nil :todo-type nil :post-blank 0 :footnote-section-p nil :archivedp nil :commentedp nil :post-affiliated 63695 :EXPORT_FILE_NAME "summary-splitter-at-eof" :title "Summary Splitter at EOF")) nil)

Will investigate more.

---

Update: Yes it is.. typing just <!--more--> in a markdown-mode buffer causes the error.

[kaushalmodi]

Closing this issue as it's not related to ox-hugo, and it's being tracked in markdown-mode repo at jrblevin/markdown-mode#327.