* lisp/textmodes/paragraphs.el (mark-paragraph): Revert
eb090f65ce (bug#45318). This restores
the behaviour from Emacs 27 -- further work is needed on this patch.
* lisp/textmodes/paragraphs.el: Use lexical-binding.
(repunctuate-sentences): Make it work non-interactively.
* test/lisp/textmodes/paragraphs-tests.el: New file.