Variable: other-window-scroll-default
other-window-scroll-default is a variable defined in window.c.
Value
nil
Documentation
Function that provides the window to scroll by C-M-v (scroll-other-window).
The function other-window-for-scrolling first tries to use
minibuffer-scroll-window and other-window-scroll-buffer.
But when both are nil, then by default it uses a neighboring window.
This variable is intended to get another default instead of next-window.
Probably introduced at or before Emacs version 29.1.
Source Code
// Defined in /usr/src/emacs/src/window.c
DEFVAR_LISP ("other-window-scroll-default", Vother_window_scroll_default,
doc: /* Function that provides the window to scroll by \\[scroll-other-window].
The function `other-window-for-scrolling' first tries to use
`minibuffer-scroll-window' and `other-window-scroll-buffer'.
But when both are nil, then by default it uses a neighboring window.
This variable is intended to get another default instead of `next-window'. */);