(normal-erase-is-backspace): Define default value.

diff --git a/lisp/simple.el b/lisp/simple.el
index 68ef955431a950145119377e348dfe35e73a2149..00005ae355b7f80127f7375a3260e8df2bbec91f 100644 (file)
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -5025,7 +5025,17 @@ the front of the list of recently selected ones."
 \f
 ;;; Handling of Backspace and Delete keys.
 
-(defcustom normal-erase-is-backspace nil
+(defcustom normal-erase-is-backspace
+  (and (not noninteractive)
+       (or (memq system-type '(ms-dos windows-nt))
+          (and (memq window-system '(x))
+               (fboundp 'x-backspace-delete-keys-p)
+               (x-backspace-delete-keys-p))
+          ;; If the terminal Emacs is running on has erase char
+          ;; set to ^H, use the Backspace key for deleting
+          ;; backward and, and the Delete key for deleting forward.
+          (and (null window-system)
+               (eq tty-erase-char ?\^H))))
   "If non-nil, Delete key deletes forward and Backspace key deletes backward.
 
 On window systems, the default value of this option is chosen