1 files changed, 9 insertions, 0 deletions

diff --git a/lisp/help-mode.el b/lisp/help-mode.el
index 9941f0604bd..2e5bbb9315b 100644
--- a/lisp/help-mode.el
+++ b/lisp/help-mode.el
@@ -648,6 +648,15 @@ For the cross-reference format, see `help-make-xrefs'."
                 (fboundp sym) (facep sym))
         (help-do-xref pos #'help-xref-interned (list sym))))))
 
+(defun help-insert-string (string)
+  "Insert STRING to the help buffer and install xref info for it.
+This function can be used to restore the old contents of the help buffer
+when going back to the previous topic in the xref stack.  It is needed
+in case when it is impossible to recompute the old contents of the
+help buffer by other means."
+  (setq help-xref-stack-item (list #'help-insert-string string))
+  (with-output-to-temp-buffer (help-buffer)
+    (insert string)))
 
 (provide 'help-mode)