bug#7185: 24.0.50; c-fill-paragraph regression

bug#7185: 24.0.50; c-fill-paragraph regression

[John Yates]

==[ Before filling comment ]==

/*
    >> abc
    >> def
*/
{
    return 0;
}

==[ Emacs 23.1.1, after filling (sub-optimal) ]==

/*
    >> abc def */
{
    return 0;
}

==[ Emacs 24.0.50.1, after filling (much worse) ]==

/*
    >> abc def */ { return 0; }


The problem seems to associated with the fact the the comment close
token (*/) is not preceded by an initial space (which, had it been
present, would have cause the opening and closing asterisks to be
aligned.

==[ Before filling paragraph ]==

/*
    >> abc
    >> def
 */
{
    return 0;
}

==[ Either Emacs, after filling (optimal) ]==

/*
    >> abc def
 */
{
    return 0;
}


In GNU Emacs 24.0.50.1 (x86_64-pc-linux-gnu, GTK+ Version 2.20.1)
 of 2010-10-08 on elegiac, modified by Debian
 (emacs-snapshot package, version 1:20101008-1)
Windowing system distributor `The X.Org Foundation', version 11.0.10706000
configured using `configure  '--build' 'x86_64-linux-gnu' '--host'
'x86_64-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib'
'--libexecdir=/usr/lib' '--localstatedir=/var'
'--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes'
'--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/24.0.50/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.0.50/site-lisp:/usr/share/emacs/site-lisp'
'--without-compress-info' '--with-x=yes' '--with-x-toolkit=gtk'
'--with-imagemagick=yes' 'build_alias=x86_64-linux-gnu'
'host_alias=x86_64-linux-gnu' 'CFLAGS=-DDEBIAN
-DSITELOAD_PURESIZE_EXTRA=5000 -g -O2' 'LDFLAGS=-g -Wl,--as-needed'
'CPPFLAGS=''

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: en_US.utf8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<help-echo> <escape> x r e p o r t - <tab> <return
>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
/usr/share/emacs/24.0.50/site-lisp/debian-startup hides
/usr/share/emacs/site-lisp/debian-startup

Features:
(shadow sort gnus-util mail-extr message sendmail regexp-opt rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mailabbrev mail-utils
gmm-utils mailheader emacsbug tooltip ediff-hook vc-hooks
lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image fringe
lisp-mode register page menu-bar rfn-eshadow timer select scroll-bar
mouse jit-lock font-lock syntax facemenu font-core frame cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev
loaddefs button minibuffer faces cus-face files text-properties overlay
md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote make-network-process dbusbind
dynamic-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty emacs)

bug#7185: 24.0.50; c-fill-paragraph regression

[Alan Mackenzie]

Hi, John,

On Sun, Oct 10, 2010 at 11:53:15AM -0400, John Yates wrote:
> ==[ Before filling comment ]==
> 
> /*
>     >> abc
>     >> def
> */
> {
>     return 0;
> }

> ==[ Emacs 23.1.1, after filling (sub-optimal) ]==
> 
> /*
>     >> abc def */
> {
>     return 0;
> }

> ==[ Emacs 24.0.50.1, after filling (much worse) ]==
> 
> /*
>     >> abc def */ { return 0; }
> 

> The problem seems to associated with the fact the the comment close
> token (*/) is not preceded by an initial space (which, had it been
> present, would have cause the opening and closing asterisks to be
> aligned.

It was actually an off-by-1 error in `c-mask-paragraph'.  It's now fixed
(I hope :-).  I'd by grateful if you could try out the fix (now in the
bzr repository), just to make sure I haven't introduced a new bug.

Thanks for such a high quality bug report!
 
-- 
Alan Mackenzie (Nuremberg, Germany).