Variable: ediff-merge-split-window-function

ediff-merge-split-window-function is a customizable variable defined in ediff-wind.el.gz.

Value

split-window-horizontally

Documentation

The function used to split the main window between buffer-A and buffer-B.

You can set it to a vertical split instead of the default horizontal split by setting this variable to split-window-vertically. You can also have your own function to do fancy splits. This variable has no effect when buffer-A/B/C are shown in different frames. In this case, Ediff will use those frames to display these buffers.

Source Code

;; Defined in /usr/src/emacs/lisp/vc/ediff-wind.el.gz
(defcustom ediff-merge-split-window-function #'split-window-horizontally
  "The function used to split the main window between buffer-A and buffer-B.
You can set it to a vertical split instead of the default horizontal split
by setting this variable to `split-window-vertically'.
You can also have your own function to do fancy splits.
This variable has no effect when buffer-A/B/C are shown in different frames.
In this case, Ediff will use those frames to display these buffers."
  :type '(choice
	  (const :tag "Split vertically" split-window-vertically)
	  (const :tag "Split horizontally" split-window-horizontally)
	  function))