I have a buffer with the 3 lines below. Notice that the long lines
contains no newlines. I selected (with the mark) the whole last line,
the one starting with "2.", and ran `fill-region`. It worked, and the
line was filled. Then I tried to do the same with the line starting with
"1.", but when I selected it and ran fill-region, nothing happened, and
it remained one long line.

If I try to fill the line starting with "1." first, before filling "2.",
it works. And after "1." I can fill "2.".

If I remove the "1." and "2." and just have two long lines instead of a
list, they can be filled in any order.

The buffer text:

* Test
1. long line long line long line long line long line long line long line
long line long line long line long line long line long line long line long
line long line long line long line long line long line
2. long line long line long line long line long line long line long line
long line long line long line long line long line long line long line long
line long line long line long line long line long line


Emacs  : GNU Emacs 25.1.1 (x86_64-pc-linux-gnu, GTK+ Version 3.18.9)
 of 2016-12-21
Package: Org mode version 9.0.5 (9.0.5-elpa @
/home/oskar/.emacs.d/elpa/org-20170210/)

current state:
==============
(setq
 org-tab-first-hook '(org-babel-hide-result-toggle-maybe
org-babel-header-arg-expand)
 org-speed-command-hook '(org-speed-command-default-hook
org-babel-speed-command-hook)
 org-occur-hook '(org-first-headline-recenter)
 org-metaup-hook '(org-babel-load-in-session-maybe)
 org-confirm-shell-link-function 'yes-or-no-p
 org-startup-indented t
 org-after-todo-state-change-hook '(org-clock-out-if-current)
 org-from-is-user-regexp "\\<Oskar Kvist\\>"
 org-src-mode-hook '(org-src-babel-configure-edit-buffer
org-src-mode-configure-edit-buffer)
 org-agenda-before-write-hook '(org-agenda-add-entry-text)
 org-babel-pre-tangle-hook '(save-buffer)
 org-mode-hook '(rainbow-delimiters-mode
                 #[0 "\300\301\302\303\304$\207"
                   [add-hook change-major-mode-hook org-show-block-all
append local] 5 "\n\n(fn)"]
                 #[0 "\300\301\302\303\304$\207"
                   [add-hook change-major-mode-hook
org-babel-show-result-all append local] 5
                   "\n\n(fn)"]
                 org-babel-result-hide-spec org-babel-hide-all-hashes)
 org-archive-hook '(org-attach-archive-delete-maybe)
 org-cycle-hook '(org-cycle-hide-archived-subtrees org-cycle-hide-drawers
                  org-cycle-show-empty-lines
org-optimize-window-after-visibility-change)
 org-M-RET-may-split-line nil
 org-todo-keywords '((sequence "TODO" "IN-PROGRESS" "DONE"))
 org-confirm-elisp-link-function 'yes-or-no-p
 org-metadown-hook '(org-babel-pop-to-session-maybe)
 org-link-parameters '(("id" :follow org-id-open)
                       ("rmail" :follow org-rmail-open :store
org-rmail-store-link)
                       ("mhe" :follow org-mhe-open :store
org-mhe-store-link)
                       ("irc" :follow org-irc-visit :store
org-irc-store-link)
                       ("info" :follow org-info-open :export
org-info-export :store
                        org-info-store-link)
                       ("gnus" :follow org-gnus-open :store
org-gnus-store-link)
                       ("docview" :follow org-docview-open :export
org-docview-export :store
                        org-docview-store-link)
                       ("bibtex" :follow org-bibtex-open :store
org-bibtex-store-link)
                       ("bbdb" :follow org-bbdb-open :export
org-bbdb-export :complete
                        org-bbdb-complete-link :store org-bbdb-store-link)
                       ("w3m" :store org-w3m-store-link) ("file+sys")
("file+emacs")
                       ("doi" :follow org--open-doi-link) ("elisp" :follow
org--open-elisp-link)
                       ("file" :complete org-file-complete-link)
                       ("ftp" :follow (lambda (path) (browse-url (concat
"ftp:" path))))
                       ("help" :follow org--open-help-link)
                       ("http" :follow (lambda (path) (browse-url (concat
"http:" path))))
                       ("https" :follow (lambda (path) (browse-url (concat
"https:" path))))
                       ("mailto" :follow (lambda (path) (browse-url (concat
"mailto:" path))))
                       ("message" :follow (lambda (path) (browse-url
(concat "message:" path))))
                       ("news" :follow (lambda (path) (browse-url (concat
"news:" path))))
                       ("shell" :follow org--open-shell-link))
 org-clock-out-hook '(org-clock-remove-empty-clock-drawer)
 )