org.el: New command `org-toggle-narrow-to-subtree'

* lisp/org.el (org-toggle-narrow-to-subtree): New command.
(org-speed-commands-default): Use the new command for the "s"
speed command.

etc/ORG-NEWS

@@ -305,7 +305,7 @@ beginning of a headline when using Org speed commands.  Now, if there
 is already a restriction at point, hitting =<= again (or =C-x C-x <=) will
 remove it.
 
-** New functions
+** New commands and functions
 
 *** ~org-insert-structure-template~
 
@@ -323,7 +323,15 @@ See docstring for details.
 
 See docstring for details.
 
-** Removed functions
+*** ~org-toggle-narrow-to-subtree~
+
+Toggle the narrowing state of the buffer: when in a narrowed state,
+widen, otherwise call ~org-narrow-to-subtree~ to narrow.
+
+This is attached to the "s" speed command, so that hitting "s" twice
+will go back to the widen state.
+
+** Removed commands and functions
 *** ~org-outline-overlay-data~
 Use ~org-save-outline-visibility~ instead.
 *** ~org-set-outline-overlay-data~
@@ -336,10 +344,12 @@ It was not used throughout code base.
 Use ~org-element-at-point~ instead.
 *** ~org-try-structure-completion~
 Org Tempo may be used as a replacement.  See details above.
-** Removed variables
+** Removed options
 
 *** org-babel-use-quick-and-dirty-noweb-expansion
 
+See [[*Change to Noweb expansion][Change to Noweb expansion]] for explanations.
+
 ** Miscellaneous
 
 *** New default value for ~org-texinfo-table-scientific-notation~

lisp/org.el

@@ -8447,6 +8447,13 @@ If yes, remember the marker and the distance to BEG."
 	       (when (and (org-at-heading-p) (not (eobp))) (backward-char 1))
 	       (point)))))))
 
+(defun org-toggle-narrow-to-subtree ()
+  "Narrow to the subtree at point or widen a narrowed buffer."
+  (interactive)
+  (if (buffer-narrowed-p)
+      (widen)
+    (org-narrow-to-subtree)))
+
 (defun org-narrow-to-block ()
   "Narrow buffer to the current block."
   (interactive)
@@ -19097,7 +19104,7 @@ COMMANDS is a list of alternating OLDDEF NEWDEF command names."
     ("c" . org-cycle)
     ("C" . org-shifttab)
     (" " . org-display-outline-path)
-    ("s" . org-narrow-to-subtree)
+    ("s" . org-toggle-narrow-to-subtree)
     ("k" . org-cut-subtree)
     ("=" . org-columns)
     ("Outline Structure Editing")