Currently, when an edit is made to a specific section of a page, or when a new section is created, that section is noted in the summary in the form /* SECTION_NAME */. When the section heading includes a wikilink, the edit summary's link still works. However, if the section heading includes an external link, it fails. See, eg, https://en.wikipedia.org/wiki/Special:Diff/891425787. Ideally, the link should still work.