Table of contents headline links are exported with incorrect references

[tylerjl]

Hi! Thanks so much for weblorg. ❤

I've found that when including a table of contents with a line like the following:

#+TOC: headlines 2

The resulting HTML includes unique org links (of the form #org865011c) rather then the cleaned-up :CUSTOM_ID values that get inserted as part of the weblorg--parse-org advice overrides.

I've managed to get it working by adding another advice-add in the function that does something like this:

(advice-add
 #'org-html--reference :around
 (lambda(fn datum info &optional named-only)
   (if (and
    (memq (org-element-type datum) '(headline))
    (not (org-element-property :CUSTOM_ID datum)))
       (if-let ((headline-slug (weblorg--slugify (org-element-property :raw-value datum))))
           (org-element-put-property datum :CUSTOM_ID headline-slug)))
   (funcall fn datum info named-only)))

So I think that something like it will probably reliably work. I can either upstream something cleaner, or if somebody knows more about what they're doing than I do (😅 ) then that's great too.