emacs-27 2035ecc 3/5: Backport: Provide missing let definition to prevent background void-variable error.

[ken manheimer]

branch: emacs-27
commit 2035ecca578f3cbcc96c314e16e21be51ddea98d
Author: Ken Manheimer <ken.manheimer@gmail.com>
Commit: Ken Manheimer <ken.manheimer@gmail.com>

    Backport: Provide missing let definition to prevent background 
void-variable error.
    
    * lisp/allout-widgets.el (allout-widgets-exposure-change-processor)
    Let-declare handled-conceal, for reference through `(symbol-value)'
    within the let body. (Because the error happens in an
    after-change-functions hook, so it is caught and reported as a message
    by allout-widgets-hook-error-handler.)
    
    (cherry picked from commit 3c410b6b4753e02269bb36914e7534eb124150dd)
---
 lisp/allout-widgets.el | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lisp/allout-widgets.el b/lisp/allout-widgets.el
index e7750b3..64f2ba5 100644
--- a/lisp/allout-widgets.el
+++ b/lisp/allout-widgets.el
@@ -988,6 +988,7 @@ Generally invoked via `allout-exposure-change-functions'."
         ;; have to distinguish between concealing and exposing so that, eg,
         ;; `allout-expose-topic's mix is handled properly.
         handled-expose
+        handled-conceal
         covered
         deactivate-mark)