master e2abbab680d: Add safeguard to 'set-variable' (bug#81244)

branch: master
commit e2abbab680ddce6326ab7f8892e93d32acdcd3b9
Author: Juri Linkov <[email protected]>
Commit: Juri Linkov <[email protected]>

    Add safeguard to 'set-variable' (bug#81244)
    
    * lisp/simple.el (set-variable): Add check with 'boundp'
    before using 'symbol-value'.  This helps in rare cases
    when used on an undefined variable name.
---
 lisp/simple.el | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/lisp/simple.el b/lisp/simple.el
index fd9ba28c762..d92abe331c8 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -10025,10 +10025,12 @@ makes it easier to edit it."
                      (call-interactively `(lambda (arg)
                                             (interactive ,prop)
                                             arg))
-                   (read-from-minibuffer prompt nil
-                                         read-expression-map t
-                                         'set-variable-value-history
-                                         (format "%S" (symbol-value var)))))))
+                   (read-from-minibuffer
+                    prompt nil
+                    read-expression-map t
+                    'set-variable-value-history
+                    (when (boundp var)
+                      (format "%S" (symbol-value var))))))))
      (list var val current-prefix-arg)))
 
   (and (custom-variable-p variable)