outline.el: Fix subtree movement.

Fixes: debbugs:19102

Co-authored-by: Stefan Monnier <monnier@iro.umontreal.ca>
* outline.el (outline-move-subtree-down): Make sure we can move
forward to find the end of the subtree and the insertion point.

2 files changed, 18 insertions, 6 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index d88ecfeb8a8..8c480190c17 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,10 @@
+2014-11-27  Stephen Berman  <stephen.berman@gmx.net>
+            Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * outline.el (outline-move-subtree-down): Make sure we can move
+        forward to find the end of the subtree and the insertion point
+        (bug#19102).
+
 2014-11-27  Leonard Randall  <leonard.a.randall@gmail.com>
 
         * textmodes/reftex-parse.el (reftex-using-biblatex-p): Make search
diff --git a/lisp/outline.el b/lisp/outline.el
index c7cad31f572..61ee7ff0f9f 100644
--- a/lisp/outline.el
+++ b/lisp/outline.el
@@ -649,27 +649,32 @@ the match data is set appropriately."
                    'outline-get-last-sibling))
         (ins-point (make-marker))
         (cnt (abs arg))
+        ;; Make sure we can move forward to find the end of the
+        ;; subtree and the insertion point.
+        (maybe-forward-char (lambda ()
+                              (if (eq (char-after) ?\n) (forward-char 1)
+                                (if (and (eobp) (not (bolp))) (insert "\n")))))
         beg end folded)
-    ;; Select the tree
+    ;; Select the tree.
     (outline-back-to-heading)
     (setq beg (point))
     (save-match-data
       (save-excursion (outline-end-of-heading)
                       (setq folded (outline-invisible-p)))
       (outline-end-of-subtree))
-    (if (= (char-after) ?\n) (forward-char 1))
+    (funcall maybe-forward-char)
     (setq end (point))
-    ;; Find insertion point, with error handling
+    ;; Find insertion point, with error handling.
     (goto-char beg)
     (while (> cnt 0)
       (or (funcall movfunc)
           (progn (goto-char beg)
-                 (error "Cannot move past superior level")))
+                 (user-error "Cannot move past superior level")))
       (setq cnt (1- cnt)))
     (if (> arg 0)
-        ;; Moving forward - still need to move over subtree
+        ;; Moving forward - still need to move over subtree.
         (progn (outline-end-of-subtree)
-               (if (= (char-after) ?\n) (forward-char 1))))
+               (funcall maybe-forward-char)))
     (move-marker ins-point (point))
     (insert (delete-and-extract-region beg end))
     (goto-char ins-point)