set-window-new-normal

set-window-new-normal is a built-in function in `C source code'.

(set-window-new-normal WINDOW &optional SIZE)

Set new normal size of WINDOW to SIZE.
WINDOW must be a valid window and defaults to the selected one.
Return SIZE.

The new normal size of WINDOW, if valid, will be shortly installed as
WINDOW's normal size (see `window-normal-size').

Note: This function does not operate on any child windows of WINDOW.