If overwrite-mode is active, point jumps 2 chars forward/backward

[lordnik22]

A speed-type session doesn't act the same when overwrite-mode is enabled.

If overwrite-mode is active, point jumps 2 chars forward/backward.

The forward-motion can be fixed (forward when inserting characters). It can be fixed by checking if the mode is active and set point to (1- end) for point-move and (- end 2) for point-stay` .

The backward-motion can not be fixed at the moment (backwards when deleting characters with backspace). For some reason delete-backward-char tries to untabify tabs where no tabs are present. It inserts 2 spaces for no obvious reason which retriggers the speed-type--change-hook. This comapres 2 spaces against the actual buffer content which marks them as error.

I assume this is a bug in the simple-package because there are not tabs to untabify anyway:

simple.el:

;; In Overwrite mode, maybe untabify while deleting
	((null (or (null overwrite-mode)
		   (<= n 0)
		   (memq (char-before) '(?\t ?\n)) <<-- this is the tab detection, which is OR-combined (therefore ignored)
		   (eobp)
		   (eq (char-after) ?\n)))
	 (let ((ocol (current-column)))
           (delete-char (- n) killflag)
	   (save-excursion
	     (insert-char ?\s (- ocol (current-column)) nil)))) ;; <<--- this inserts the 2 spaces for no reason