scratch/so-long-updates bcf697b 5/6: * lisp/so-long.el (so-long): Firstly revert the existing action, if any

[Phil]

branch: scratch/so-long-updates
commit bcf697b6690ce46ec081b21dad3591b117339468
Author: Phil Sainty <address@hidden>
Commit: Phil Sainty <address@hidden>

    * lisp/so-long.el (so-long): Firstly revert the existing action, if any
    
    If multiple actions were to be layered on top of one another, we would
    lose the ability to revert to the normal state.
    
    This makes `so-long' consistent with the action commands in the menu.
    
    A custom action combining multiple other actions could be defined, if
    such behaviour was desired.
---
 lisp/so-long.el | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/lisp/so-long.el b/lisp/so-long.el
index 6928c90..e80abc7 100644
--- a/lisp/so-long.el
+++ b/lisp/so-long.el
@@ -1576,8 +1576,12 @@ This command is called automatically when long lines are 
detected, when
 
 The effects of the action can be undone by calling `so-long-revert'.
 
-If ACTION is provided, it is used instead of `so-long-action'.  With a prefix
-argument, select the action to use interactively."
+If ACTION is provided, it is used instead of `so-long-action'.
+
+With a prefix argument, select the action to use interactively.
+
+If an action was already active in the buffer, it will be reverted before
+invoking the new action."
   (interactive
    (list (and current-prefix-arg
               (intern
@@ -1587,6 +1591,10 @@ argument, select the action to use interactively."
   ;; Ensure that `so-long-deferred' only triggers `so-long' once (at most).
   (remove-hook 'window-configuration-change-hook #'so-long :local)
   (unless so-long--calling
+    ;; Revert the existing action, if any.
+    (when so-long--active
+      (so-long-revert))
+    ;; Invoke the new action.
     (let ((so-long--calling t))
       (so-long--ensure-enabled)
       ;; ACTION takes precedence if supplied.