bug#20569: 24.5; Vertical scroll bar is shorter than frame in info buffer

[Eli Zaretskii <eliz@gnu.org>]

> From: nljlistbox2@gmail.com (N. Jackson)
> Date: Thu, 14 May 2015 10:31:07 -0300
> 
> At 05:11 -0300 on Thursday 2015-05-14, Jan D. wrote:
> 
> > The top row is a header row, it does not scroll, so there is no point
> > in having the scroll bar extend into it.
> 
> It is visually unappealing.
> 
> More importantly, it is inconsistent with usage in other software.
> 
> For example, in a GUI file management program such as Dolphin or
> Nautilus the top row of the client area of the window is also a header (
> it contains the field headings such as "Name", "Date", and
> "Permissions"), yet the scroll bar extends past this header to meet up
> with the decorations across the top of the window.

If the scroll bar extended past the header line, users would expect
that line to scroll, which it doesn't.

Anyway, this is how the header line was designed and implemented in
Emacs.  We have tabulated-list-mode for the other kind.  The Info
reader uses the header line for a good reason: it shows there stuff
that needs to be always visible, so it cannot be the first line of the
buffer, or behave like one.