Re: re-search bug?

[Kenichi Handa <handa@m17n.org>]

In article <E1CwmQS-0003Eo-S0@fencepost.gnu.org>, Richard Stallman <rms@gnu.org> writes:

>     It seems that the current code in casefiddle.c has a serious
>     bug in supporting this kind of case-mapping.

>     i <--up/downcase--> I
>     DOTLESS-i --upcase-> I
>     I-WITH-DOT-ABOVE --downcase-> i

> Do you want to debug the serious bug?

I can't work on it at the moment because I'll soon go abroad
and be off-line for a week.

Anyway, there's a possibility that the bug is not in
casefiddle.c but in case-fold searching and regexp matching
functions.  I'm not sure.

> If you send me a precise test case, I could try to debug it.

Please evaluate the attached code.  Then try these:

(test-regexp) => 1   ; correct
(test-search) => nil ; correct
(setup-case-table)
(test-regexp) => nil ; incorrect
(test-search) => nil ; incorrect
(recover-case-table)
(test-regexp) => 1   ; correct
(test-search) => nil ; correct

---
Ken'ichi HANDA
handa@m17n.org

(require 'case-table)

(defvar original-case-table (copy-case-table (standard-case-table)))
(defvar dotted-I (make-char 'latin-iso8859-9 ?\335))
(defvar dotless-i (make-char 'latin-iso8859-9 ?\375))

(defun setup-case-table ()
  (let ((tbl (standard-case-table)))
    (set-downcase-syntax dotted-I ?i tbl)
    (set-upcase-syntax ?I dotless-i tbl)))

(defun recover-case-table ()
  (set-standard-case-table (copy-case-table original-case-table)))

(defun test-regexp ()
  (with-temp-buffer
    (let ((case-fold-search t))
      (insert "i.")
      (re-search-backward "i\\." nil t))))

(defun test-search ()
  (with-temp-buffer
    (let ((case-fold-search t))
      (insert dotless-i)
      (search-backward "i" nil t))))