+ The @dfn{total height} of a window is the number of lines comprising
+the window's body, the header line, the mode line and the bottom divider
+(if any). Note that the height of a frame is not the same as the height
+of its root window (@pxref{Windows and Frames}), since a frame may also
+contain an echo area, a menu bar, and a tool bar (@pxref{Size and
+Position}).
+
+@defun window-total-height &optional window round
+This function returns the total height, in lines, of the window
+@var{window}. If @var{window} is omitted or @code{nil}, it defaults to
+the selected window. If @var{window} is an internal window, the return
+value is the total height occupied by its descendant windows.
+
+ If a window's pixel height is not an integral multiple of its frame's
+default character height, the number of lines occupied by the window is
+rounded internally. This is done in a way such that, if the window is a
+parent window, the sum of the total heights of all its child windows
+internally equals the total height of their parent. This means that
+although two windows have the same pixel height, their internal total
+heights may differ by one line. This means also, that if this window is
+vertically combined and has a right sibling, the topmost row of that
+sibling can be calculated as the sum of this window's topmost row and
+total height (@pxref{Coordinates and Windows})
+
+ If the optional argument @var{round} equals @code{ceiling}, this
+function returns the smallest integer larger than @var{window}'s pixel
+height divided by the character height of @var{window}'s frame; if it is
+@code{floor}, it returns the largest integer smaller than @var{window}'s
+pixel height divided by the character height of @var{window}'s frame.
+Any other value of @var{round} means to return the internal value of the
+total height of @var{window}.
+@end defun
+