bug#9758: 24.0.90; Elisp doc strings and fill-paragraph on region

[Stephen Berman]

The doc string of fill-paragraph-function notes that it affects
fill-paragraph but not fill-region.  But fill-paragraph itself calls
fill-region, and one case where this asymmetry is problematic is Elisp
doc strings.  Typing `M-q' with point within a doc string in Emacs Lisp
mode calls lisp-fill-paragraph (via fill-paragraph-function) with
fill-column set to emacs-lisp-docstring-fill-column.  But selecting (and
highlighting) a region within a doc string calls fill-region, which uses
either the local, global or customized value of fill-column, which is
most likely different from emacs-lisp-docstring-fill-column.  In this
case, using `M-q' on a highlighted region of a doc string (say, several
paragraphs of a long doc string) produces an ill-formatted result.  (The
doc string of fill-paragraph-function says "it is often better to use
some other hook, such as `fill-forward-paragraph-function'," but I don't
see how that would help in this case.)

In GNU Emacs 24.0.90.6 (i686-suse-linux-gnu, GTK+ Version 2.22.1)
 of 2011-10-13 on escher
Windowing system distributor `The X.Org Foundation', version 11.0.10903000
configured using `configure  '--without-toolkit-scroll-bars' 'CFLAGS=-g''