emacs-29 25c65e6b586 1/4: Backport: Fix xref-clear-marker-stack refactoring mistake

[Dmitry Gutov]

branch: emacs-29
commit 25c65e6b58692a628556d5d1147d3f54ba603351
Author: Mattias Engdegård <mattiase@acm.org>
Commit: Dmitry Gutov <dgutov@yandex.ru>

    Backport: Fix xref-clear-marker-stack refactoring mistake
    
    * lisp/progmodes/xref.el (xref-clear-marker-stack):
    Clear the history correctly.  Changing a lexical variable has no effect.
    
    (cherry picked from commit dfdc0f5fb7b10e737c3c8e2bdb1eb873a1e91bd7)
---
 lisp/progmodes/xref.el | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lisp/progmodes/xref.el b/lisp/progmodes/xref.el
index 916d83d407b..4db0df6c3b8 100644
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -568,7 +568,8 @@ This can be used from `xref-after-jump-hook', for 
instance.")
     (dolist (l (list (car history) (cdr history)))
       (dolist (m l)
         (set-marker m nil nil)))
-    (setq history (cons nil nil)))
+    (setcar history nil)
+    (setcdr history nil))
   nil)
 
 ;;;###autoload