BUG [Emacs 21.1] Variable minibuffer-scroll-overlap not defined

[Francis Litterio]

The etc/NEWS files for Emacs 21.1 describes variable
minibuffer-scroll-overlap as follows:

  ** When you type a long line in the minibuffer, and the minibuffer
  shows just one line, automatically scrolling works in a special way
  that shows you overlap with the previous line of text.  The variable
  minibuffer-scroll-overlap controls how many characters of overlap
  it should show; the default is 20.

but there is no variable by that name!
--
Francis Litterio
franl-remove@world.omit-this.std.com