bug#11640: 24.1.50; texinfo-format-printindex fails on Windows with Windows's sort

[Juanma Barranquero <lekktu@gmail.com>]

On Thu, Jun 7, 2012 at 6:23 PM, Eli Zaretskii <eliz@gnu.org> wrote:

> Seriously, I find it hard to believe that performance matters in this
> case, especially since texinfmt.el is no longer the main recommended
> way of producing Info from Texinfo, which is why it doesn't get
> updated with the latest features of the Texinfo language.

I'm perfectly willing to believe you. As I said, I don't know why was
it done otherwise.

> Stefan, Chong, any objections to sorting the indices in Lisp in this
> case?

The patch is even simpler.


2012-06-07  Juanma Barranquero  <lekktu@gmail.com>

	* textmodes/texinfmt.el: Use internal sort (partial revert of revno:89810).
	(texinfo-sort-region, texinfo-sort-startkeyfun): Restore functions.
	(texinfo-format-printindex): Use `texinfo-sort-region' instead of
	calling external sort utility.


=== modified file 'lisp/textmodes/texinfmt.el'
--- lisp/textmodes/texinfmt.el	2012-04-09 13:05:48 +0000
+++ lisp/textmodes/texinfmt.el	2012-06-07 18:38:56 +0000
@@ -2958,6 +2958,28 @@
     ("ky" . texinfo-format-kindex)))

 \f
+;;; Sort and index
+
+;; Sort an index which is in the current buffer between START and END.
+(defun texinfo-sort-region (start end)
+  (require 'sort)
+  (save-restriction
+    (narrow-to-region start end)
+    (goto-char (point-min))
+    (sort-subr nil 'forward-line 'end-of-line 'texinfo-sort-startkeyfun)))
+
+;; Subroutine for sorting an index.
+;; At start of a line, return a string to sort the line under.
+(defun texinfo-sort-startkeyfun ()
+  (let ((line (buffer-substring-no-properties (point) (line-end-position))))
+    ;; Canonicalize whitespace and eliminate funny chars.
+    (while (string-match "[ \t][ \t]+\\|[^a-z0-9 ]+" line)
+      (setq line (concat (substring line 0 (match-beginning 0))
+                         " "
+                         (substring line (match-end 0)))))
+    line))
+
+\f
 ;;; @printindex

 (put 'printindex 'texinfo-format 'texinfo-format-printindex)
@@ -2974,7 +2996,7 @@
     (insert "\n* Menu:\n\n")
     (setq opoint (point))
     (texinfo-print-index nil indexelts)
-    (shell-command-on-region opoint (point) "sort -fd" 1)))
+    (texinfo-sort-region opoint (point))))

 (defun texinfo-print-index (file indexelts)
   (while indexelts