*** empty log message ***

1 files changed, 37 insertions, 1 deletions

diff --git a/lisp/textmodes/outline.el b/lisp/textmodes/outline.el
index d56df6a1ff6..47194a1c52d 100644
--- a/lisp/textmodes/outline.el
+++ b/lisp/textmodes/outline.el
@@ -357,7 +357,43 @@ If FLAG is nil then text is shown, while if FLAG is t the text is hidden."
     (save-excursion
       (goto-char from)
       (end-of-line)
-      (put-text-property (point) to 'invisible flag))))
+      (outline-discard-overlays (point) to 'outline)
+      (if flag
+          (let ((o (make-overlay (point) to)))
+            (overlay-put o 'invisible flag)
+            (overlay-put o 'outline t))))))
+
+(defun outline-discard-overlays (beg end prop)
+  (if (< end beg)
+      (setq beg (prog1 end (setq end beg))))
+  (save-excursion
+    (goto-char beg)
+    (while (< (point) end)
+      (let ((overlays (overlays-at (point))))
+        (while overlays
+          (let ((o (car overlays)))
+            (if (overlay-get o prop)
+                ;; Either push this overlay outside beg...end
+                ;; or split it to exclude beg...end
+                ;; or delete it entirely (if it is contained in beg...end).
+                (if (< (overlay-start o) beg)
+                    (if (> (overlay-end o) end)
+                        (let ((o1 (outline-copy-overlay o)))
+                          (move-overlay o1 (overlay-start o1) beg)
+                      (move-overlay o (overlay-start o) beg)))
+                  (if (> (overlay-end o) end)
+                      (move-overlay o end (overlay-end o))
+                    (delete-overlay o)))))
+          (setq overlays (cdr overlays))))
+      (goto-char (next-overlay-change (point))))))
+
+(defun outline-copy-overlay (o)
+  (let ((o1 (make-overlay (overlay-start o) (overlay-end o)))
+        (props (overlay-properties o)))
+    (while props
+      (overlay-put o1 (car props) (nth 1 props))
+      (setq props (cdr (cdr props))))
+    o1))
 
 (defun hide-entry ()
   "Hide the body directly following this heading."