To reproduce, make the following two admin settings:
enable markdown linkify: true
markdown linkify tlds: none (that is, delete all TLDs that are set by default)
Then do a “Rebuild HTML” for any post that includes a full sentence, and note that the last word at the end of every sentence, and the following dot, is now linkified. Example:
Alternatively, you could allow markdown linkify tlds to be empty, but treat that case internally with the same code used when enable markdown linkify: false has been set.
You’re raising a good point there
I was just experimenting how to get rid of the “convert URL to title of linked page” behavior. Later found it’s called Inline Onebox, and cannot be disabled for Discourse-internal links.