Hello,

I really enjoy the adaptive-wrap package, I find that it usually makes
long lines significantly more legible than plain visual-line-mode.

In some situations though, I think the wrap prefix could be improved.


1. When the fill prefix does not end with a space and extra-indent > 0
======================================================================

When extra indent is requested, the code uses the last character of
(fill-context-prefix beg end) as the padding character.

E.g. in *scratch*, from emacs -Q -rv:

#+begin_src elisp
(progn
  (package-initialize)
  (setq adaptive-wrap-extra-indent 2)
  (visual-line-mode)
  (adaptive-wrap-prefix-mode))
;;Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. 
#+end_src

See first screenshot.