Make 'buffer-last-name' work better after 'find-alternate-file' (Bug#68235)

* lisp/files.el (find-alternate-file): Before killing the previous
buffer, try to restore its name and filenames (Bug#68235).

(cherry picked from commit 9a79db506e39c02daa81629f0b224a86fad2b3c6)

diff --git a/lisp/files.el b/lisp/files.el
index 82544bd20be87c39f49aead952a081a27e68b897..605d9b03d05862b18ad5d635cb2ee910cc3292df 100644 (file)
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -2133,6 +2133,15 @@ killed."
        (rename-buffer oname)))
     (unless (eq (current-buffer) obuf)
       (with-current-buffer obuf
+       (unless (get-buffer oname)
+         ;; Restore original's buffer name so 'kill-buffer' can use it
+         ;; to assign its last name (Bug#68235).
+         (rename-buffer oname))
+       ;; Restore original buffer's file names so they can be still
+       ;; used when referencing the now defunct buffer (Bug#68235).
+       (setq buffer-file-name ofile)
+       (setq buffer-file-number onum)
+       (setq buffer-file-truename otrue)
        ;; We already ran these; don't run them again.
        (let (kill-buffer-query-functions kill-buffer-hook)
          (kill-buffer obuf))))))