bug#1012: calculate-lisp-indent

[Markus Sauermann]

Hello,

I found a bug concerning the function calculate-lisp-indent in lisp-mode.el.
It is triggered in the following scenarios (-!- marks the point):

---begin scenario 1 buffer *scratch*---
(,@foo
 :bar)-!-
---end scenario 1 buffer *scratch*---

---begin scenario 2 buffer *scratch*---
( foo
 :bar)-!-
---end scenario 2 buffer *scratch*---

Using <tab> (bound to the function lisp-indent-line) triggers the
following error in both scenarios:

---begin error---
forward-sexp: Scan error: "Containing expression ends prematurely", 192, 192
---end error---



I traced this bug to the function calculate-lisp-indent.

As far as I understand the code, the characters ",@" in scenario 1 and
the spaces in scenario 2 are not treated correctly.

In this E-Mail I included a patch, that solves the problems for me, and
was created with the command

mhoram@revelstone:~/emacs/trunk/emacs/lisp$ cvs diff -c >
~/emacs-bugreport.txt



The patch works for scenario 1 by an additional call of the
(backward-prefix-chars) function, which sets point back to the beginning
of ",@".
For scenario 2 the addition of "\\|([ \t]+" solves the problem, by not
entering the while-loop (and thus calling the function (forward-sexp
-1)), if there are only spaces between the "(" and the first object.



Regards,
Markus Sauermann



In GNU Emacs 22.3.1 (i386-mingw-nt6.0.6001)
 of 2008-09-06 on SOFT-MJASON
Windowing system distributor `Microsoft Corp.', version 6.0.6001
configured using `configure --with-gcc (3.4)'

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: DEU
  locale-coding-system: cp1252
  default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  encoded-kbd-mode: t
  tooltip-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
  auto-compression-mode: t
  line-number-mode: t

Recent input:
<help-echo> <help-echo> <help-echo> <help-echo> q (
, @ f o o <return> <tab> : b a r ) <tab> M-x r e p
o r t <tab> <return>

Recent messages:
("D:\\Uninstalled\\emacs-22.3\\bin\\emacs.exe" "-q")
Loading encoded-kb...done
For information about GNU Emacs and the GNU system, type C-h C-a.
forward-sexp: Scan error: "Containing expression ends prematurely", 192, 192
Loading emacsbug...
Loading regexp-opt...done
Loading emacsbug...done


-- 
Markus Sauermann      E-Mail: info@sauermann-consulting.de
Clemensstr. 55 Rgb.   Web: http://www.sauermann-consulting.de
80803 München         Tel: 089/337707, 0179/9879005, Fax: 089/38476434

Index: ChangeLog
===================================================================
RCS file: /sources/emacs/emacs/lisp/ChangeLog,v
retrieving revision 1.14493
diff -c -r1.14493 ChangeLog
*** ChangeLog   20 Sep 2008 22:09:39 -0000      1.14493
--- ChangeLog   21 Sep 2008 17:08:59 -0000
***************
*** 1,3 ****
--- 1,9 ----
+ 2008-09-21  Markus Sauermann <markus@sauermann-consulting.de>
+ 
+       * emacs-lisp/lisp-mode.el (calculate-lisp-indent):
+       Fix indentation problem with keyword symbols when a list starts
+       with ,@ or spaces.
+ 
  2008-09-20  Vincent Belaïche  <vincent.b.1@hotmail.fr>
  
        * calc/calc-vec.el (calcFunc-venum): Properly handle intervals.
Index: emacs-lisp/lisp-mode.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/emacs-lisp/lisp-mode.el,v
retrieving revision 1.226
diff -c -r1.226 lisp-mode.el
*** emacs-lisp/lisp-mode.el     20 Sep 2008 21:54:44 -0000      1.226
--- emacs-lisp/lisp-mode.el     21 Sep 2008 17:09:04 -0000
***************
*** 1027,1033 ****
                       ;; where it begins, so find that one, instead.
                       (save-excursion
                         (goto-char calculate-lisp-indent-last-sexp)
!                        (while (and (not (looking-back "^[ \t]*"))
                                     (or (not containing-sexp)
                                         (< (1+ containing-sexp) (point))))
                           (forward-sexp -1)
--- 1027,1034 ----
                       ;; where it begins, so find that one, instead.
                       (save-excursion
                         (goto-char calculate-lisp-indent-last-sexp)
!                        (backward-prefix-chars)
!                        (while (and (not (looking-back "^[ \t]*\\|([ \t]+"))
                                     (or (not containing-sexp)
                                         (< (1+ containing-sexp) (point))))
                           (forward-sexp -1)