line-spacing doc string does not explain nil value

[Drew Adams]

Doc string for `line-spacing':

 line-spacing is a variable defined in `C source code'.
 Its value is nil

 Documentation:
 Additional space to put between lines when displaying a buffer.
 The space is measured in pixels, and put below lines on window systems.
 If value is a floating point number, it specifies the spacing relative
 to the default frame line height.

The default value is nil but there is no explanation of what that means. The
doc string should say, like the Customize tags say, that nil means that no
additional space is used between lines.



In GNU Emacs 22.0.50.1 (i386-mingw-nt5.1.2600)
 of 2006-03-20 on W2ONE
X server distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4) --cflags -Id:/g/include'

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: ENU
  locale-coding-system: cp1252
  default-enable-multibyte-characters: t

Major mode: Dired by name

Minor modes in effect:
  encoded-kbd-mode: t
  tooltip-mode: t
  auto-compression-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  line-number-mode: t

Recent input:
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<menu-bar> <help-menu> <report-emacs-bug>

Recent messages:
(C:\Emacs-22-2006-03-20\bin\emacs.exe -q --no-site-file --debug-init
C:\drews-lisp-20)
Loading encoded-kb...done
For information about the GNU Project and its goals, type C-h C-p.
Loading dired...
Loading regexp-opt...done
Loading dired...done
Loading emacsbug...done