Prevent filling before a "n" macro where it could create list items

* lisp/org.el (org-fill-n-macro-as-item-nobreak-p): New function.
(org-setup-filling): Use new function.

* testing/lisp/test-org.el (test-org/fill-element): Add tests.

Reported-by: Kaushal Modi <kaushal.modi@gmail.com>
<http://permalink.gmane.org/gmane.emacs.orgmode/113587>

lisp/org.el

@@ -22905,6 +22905,7 @@ assumed to be significant there."
      (org-uniquify
       (append fill-nobreak-predicate
 	      '(org-fill-line-break-nobreak-p
+		org-fill-n-macro-as-item-nobreak-p
 		org-fill-paragraph-with-timestamp-nobreak-p)))))
   (let ((paragraph-ending (substring org-element-paragraph-separate 1)))
     (setq-local paragraph-start paragraph-ending)
@@ -22927,6 +22928,12 @@ assumed to be significant there."
   (and (org-at-timestamp-p 'lax)
        (not (looking-at org-ts-regexp-both))))
 
+(defun org-fill-n-macro-as-item-nobreak-p ()
+  "Non-nil when a new line at point would create a new list."
+  ;; During export, a "n" macro followed by a dot or a closing
+  ;; parenthesis can end up being parsed as a new list item.
+  (looking-at-p "[ \t]*{{{n\\(?:([^\n)]*)\\)?}}}[.)]\\(?:$\\| \\)"))
+
 (declare-function message-in-body-p "message" ())
 (defvar orgtbl-line-start-regexp) ; From org-table.el
 (defun org-adaptive-fill-function ()

testing/lisp/test-org.el

@@ -565,16 +565,45 @@
 	      (org-fill-element)
 	      (buffer-string)))))
   ;; Do nothing at affiliated keywords.
-  (org-test-with-temp-text "#+NAME: para\nSome\ntext."
-    (let ((fill-column 20))
-      (org-fill-element)
-      (should (equal (buffer-string) "#+NAME: para\nSome\ntext."))))
+  (should
+   (equal "#+NAME: para\nSome\ntext."
+	  (org-test-with-temp-text "#+NAME: para\nSome\ntext."
+	    (let ((fill-column 20))
+	      (org-fill-element)
+	      (buffer-string)))))
   ;; Do not move point after table when filling a table.
   (should-not
    (org-test-with-temp-text "| a | b |\n| c | d |\n"
      (forward-char)
      (org-fill-element)
-     (eobp))))
+     (eobp)))
+  ;; Do not fill "n" macro, with or without arguments, followed by
+  ;; a dot or a closing parenthesis since it could be confused with
+  ;; a numbered bullet.
+  (should-not
+   (equal "123456789\n{{{n}}}."
+	  (org-test-with-temp-text "123456789 {{{n}}}."
+	    (let ((fill-column 10))
+	      (org-fill-element)
+	      (buffer-string)))))
+  (should-not
+   (equal "123456789\n{{{n}}}\)"
+	  (org-test-with-temp-text "123456789 {{{n}}}\)"
+	    (let ((fill-column 10))
+	      (org-fill-element)
+	      (buffer-string)))))
+  (should-not
+   (equal "123456789\n{{{n()}}}."
+	  (org-test-with-temp-text "123456789 {{{n()}}}."
+	    (let ((fill-column 10))
+	      (org-fill-element)
+	      (buffer-string)))))
+  (should-not
+   (equal "123456789\n{{{n(counter)}}}."
+	  (org-test-with-temp-text "123456789 {{{n(counter)}}}."
+	    (let ((fill-column 10))
+	      (org-fill-element)
+	      (buffer-string))))))
 
 (ert-deftest test-org/auto-fill-function ()
   "Test auto-filling features."