emacs -Q, I strike
C-x 4 b which invoke
(switch-to-buffer-other-window) and display the other window vertically as
I reference it's source code
(defun switch-to-buffer-other-window (buffer-or-name &optional norecord) (interactive (list (read-buffer-to-switch "Switch to buffer in other window: "))) (let ((pop-up-windows t)) (pop-to-buffer buffer-or-name t norecord)))
It apply the procedure of
How could use "C-x 4 b" pop up the other window which display horizontally instead of vertically?