Don't save/restore font-backend in framesets (bug#38442)

* lisp/frameset.el (frameset-persistent-filter-alist):
Add :never filter for `font-backend'.

1 files changed, 3 insertions, 0 deletions

diff --git a/lisp/frameset.el b/lisp/frameset.el
index 9a7a75f5efc..dc59afd0c92 100644
--- a/lisp/frameset.el
+++ b/lisp/frameset.el
@@ -456,6 +456,9 @@ DO NOT MODIFY.  See `frameset-filter-alist' for a full description.")
      (client                      . :never)
      (delete-before               . :never)
      (font                        . frameset-filter-font-param)
+     ;; Don't save font-backend because we cannot guarantee the new
+     ;; session will support the saved backend anyway.  (Bug#38442)
+     (font-backend                . :never)
      (foreground-color            . frameset-filter-sanitize-color)
      (frameset--text-pixel-height . :save)
      (frameset--text-pixel-width  . :save)