window-safe-min-size

window-safe-min-size is a compiled Lisp function in `window.el'.

(window-safe-min-size &optional WINDOW HORIZONTAL PIXELWISE)

Return safe minimum size of WINDOW.
WINDOW must be a valid window and defaults to the selected one.
Optional argument HORIZONTAL non-nil means return the minimum
number of columns of WINDOW; otherwise return the minimum number
of WINDOW's lines.

Optional argument PIXELWISE non-nil means return the minimum pixel-size
of WINDOW.