From 89df771a910b5d58fc667a85b4ce58a8d7ff94f5 Mon Sep 17 00:00:00 2001
From: Adam Porter <adam@alphapapa.net>
Date: Tue, 12 Mar 2024 16:01:57 -0500
Subject: [PATCH] * lisp/emacs-lisp/vtable.el (vtable-update-object): Ensure
 found obj

The OLD-OBJECT may not be found in the table, so SEQ-POSITION may return
nil, in which case ELT should not be called.
---
 lisp/emacs-lisp/vtable.el | 44 +++++++++++++++++++--------------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/lisp/emacs-lisp/vtable.el b/lisp/emacs-lisp/vtable.el
index 5cf8d8854bb..15a430f5c26 100644
--- a/lisp/emacs-lisp/vtable.el
+++ b/lisp/emacs-lisp/vtable.el
@@ -300,28 +300,28 @@ vtable-update-object
         (error "Can't find the old object"))
       (setcar (cdr objects) object))
     ;; Then update the cache...
-    (let* ((line-number (seq-position (car (vtable--cache table)) old-object
-                                      (lambda (a b)
-                                        (equal (car a) b))))
-           (line (elt (car (vtable--cache table)) line-number)))
-      (unless line
-        (error "Can't find cached object"))
-      (setcar line object)
-      (setcdr line (vtable--compute-cached-line table object))
-      ;; ... and redisplay the line in question.
-      (save-excursion
-        (vtable-goto-object old-object)
-        (let ((keymap (get-text-property (point) 'keymap))
-              (start (point)))
-          (delete-line)
-          (vtable--insert-line table line line-number
-                               (nth 1 (vtable--cache table))
-                               (vtable--spacer table))
-          (add-text-properties start (point) (list 'keymap keymap
-                                                   'vtable table))))
-      ;; We may have inserted a non-numerical value into a previously
-      ;; all-numerical table, so recompute.
-      (vtable--recompute-numerical table (cdr line)))))
+    (if-let ((line-number (seq-position (car (vtable--cache table)) old-object
+                                        (lambda (a b)
+                                          (equal (car a) b))))
+             (line (elt (car (vtable--cache table)) line-number)))
+        (progn
+          (setcar line object)
+          (setcdr line (vtable--compute-cached-line table object))
+          ;; ... and redisplay the line in question.
+          (save-excursion
+            (vtable-goto-object old-object)
+            (let ((keymap (get-text-property (point) 'keymap))
+                  (start (point)))
+              (delete-line)
+              (vtable--insert-line table line line-number
+                                   (nth 1 (vtable--cache table))
+                                   (vtable--spacer table))
+              (add-text-properties start (point) (list 'keymap keymap
+                                                       'vtable table))))
+          ;; We may have inserted a non-numerical value into a previously
+          ;; all-numerical table, so recompute.
+          (vtable--recompute-numerical table (cdr line)))
+      (error "Can't find cached object in vtable"))))
 
 (defun vtable-remove-object (table object)
   "Remove OBJECT from TABLE.
-- 
2.30.2