Clear buffer-undo-list when showing xrefs

* lisp/progmodes/xref.el (xref--show-xref-buffer): Clear
buffer-undo-list and temporarily bind it to t while rendering the
buffer contents.

diff --git a/lisp/progmodes/xref.el b/lisp/progmodes/xref.el
index b5632af13abfe20896da48e3b5823ff841a4a1dc..540c7b0e92573e518fc8910a0ac63479d860bf01 100644 (file)
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -687,7 +687,9 @@ Return an alist of the form ((FILENAME . (XREF ...)) ...)."
 (defun xref--show-xref-buffer (xrefs alist)
   (let ((xref-alist (xref--analyze xrefs)))
     (with-current-buffer (get-buffer-create xref-buffer-name)
-      (let ((inhibit-read-only t))
+      (setq buffer-undo-list nil)
+      (let ((inhibit-read-only t)
+            (buffer-undo-list t))
         (erase-buffer)
         (xref--insert-xrefs xref-alist)
         (xref--xref-buffer-mode)