follow-calc-win-end

follow-calc-win-end is a compiled Lisp function in `follow.el'.

(follow-calc-win-end &optional WIN)

Calculate the end position for window WIN.
Return (END-POS END-OF-BUFFER).

Actually, the position returned is the start of the line after
the last fully-visible line in WIN. If WIN is nil, the selected
window is used.