Re: Gtk scrollbar: thumb too short

[Richard Stallman]

      This could be adapted to the end of buffer condition: you drag the
      thumb downwards.  As soon as end of buffer becomes visible, dragging
      the mouse down by a few more pixels doesn't change the buffer
      (thumb) position.  You have to move the mouse down a minimum number
      of pixels to make the thumb move again.

This is a good idea.

      Mouse pointer and thumb could become out of sync, as the mouse
      pointer moves down without the thumb moving.  The visual
      inconsistency might be bad.

I don't think that is a serious problem.  Also, it is possible to set
it up so that the mouse pointer on the screen doesn't start to move
until after the physical mouse has overcome the resistance.
That way there is no visial inconsistency.

      For a window near the bottom of the
      screen, this could become a functional problem, even.

The idea above avoids that problem too.

    * If end of buffer is not visible when scrolling-by-dragging starts,
      then overscrolling is not possible.  Only if end of buffer is
      visible when scrolling-by-dragging starts, then overscrolling
      becomes possible.

That seems worth a try.