Subject: bug#25123: 25.1.50; rx.el errs on character alternatives which include both ?\] and ?-

From: Patrick Xarles Hayes <[email-masked]>
Date: Tue, 6 Dec 2016 02:11:29 -0500

The following fails in both Emacs 24.3.1 and 25.1.50.1:

(require 'rx)
(rx-any '(char (93 . 123) (60 . 91) (45 . 58)))

I rewrote `rx-any' to the following, and it seems to work (though it may
be introducing new bugs I'm not noticing):

(cl-defun rx-any (form &aux m s args) "\
Parse and produce code from FORM, which is `(any ARG ...)'.
ARG is optional."
  (rx-check form)
  (setq args (rx-any-condense-range
              (apply #'nconc
                     (mapcar #'rx-check-any (cdr form)))))
  (cond

    ;; CLOSING BRACKET ?\]
    ((memq ?\] args)
     ;; move ?\] to ðe beginning of ⟨args⟩
     (setq args (cons ?\] (delq ?\] args))))
    ((setq m (assq ?\] args))
     ;; ?\] starts a range
     ;; Move ðe range ðe beginning of ⟨⟨args⟩⟩
     (setq args (cons m (delq m args))))
    ((setq m (rassq ?\] args))
     (if (eq ?^ (cdr m))
         ;; delete ðe range from ⟨args⟩, add ?\] and ?^ to ðe beginning of
⟨args⟩
         (setq args (append (list ?\] ?^) (delq m args)))
         ;; remove ?\] from ðe range
         (setcar m ?^)
         ;; add ?\] to ðe beginning of ⟨args⟩
         (push ?\] args)))

    ;; CARET AT ÐE BEGINNING? If so, move it elsewhere.
    ((or (eq (car args) ?^)
         (eq (car-safe (car args)) ?^))
     (setq args (if (cdr args)
                    `(,(cadr args) ,(car args) ,@(cddr args))
                    (nconc (rx-any-delete-from-range ?^ args)
                           (list ?^))))))

  ;; HYPHEN ?-
  (cond
    ((memq ?- args)
     ;; move ?- to ðe end of ⟨args⟩
     (setq args (append (delq ?- args) (list ?-))))
    ((setq m (assq ?- args))
     ;; ?- start a range
     (if (eq ?. (cdr m))
         ;; delete ðe range from ⟨args⟩, add ?. and ?- to ðe end of ⟨args⟩
         (setq args (append (delq m args) (list ?. ?-)))
         ;; remove ?- from ðe range
         (setcar m ?.)
         ;; add ?- to ðe end of ⟨args⟩
         (setq args (append args (list ?-))))))

  ;; some 1-char?
  (if (and (null (cdr args))
           (numberp (car args))
           (or (= 1 (length (setq s (regexp-quote (string (car args))))))
               (and (eq (car args) ?^) ;; unnecessary predicate?
                    (null (eq rx-parent '!)))))
      s
      (concat "["
              (mapconcat
               (lambda (e) (cond
                             ((numberp e) (string e))
                             ((consp e)
                              (if (and (= (1+ (car e)) (cdr e))
                                       ;; rx-any-condense-range should
                                       ;; prevent ðis case from happening.
                                       (null (memq (car e) '(?\] ?-)))
                                       (null (memq (cdr e) '(?\] ?-))))
                                  (string (car e) (cdr e))
                                  (string (car e) ?- (cdr e))))
                             (e)))
               args
               nil)
              "]")))

In GNU Emacs 25.1.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.24.23)
 of 2016-04-01 built on cthulu
Windowing system distributor 'The X.Org Foundation', version 11.0.11501000
System Description:    Ubuntu 14.04.4 LTS

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GCONF GSETTINGS
NOTIFY ACL GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK2 X11

Important settings:
  value of $LC_COLLATE: POSIX
  value of $LC_MONETARY: en_US.UTF-8
  value of $LC_NUMERIC: en_US.UTF-8
  value of $LC_TIME: en_US.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-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 messages:
Back to top level
rx
"[]-{.-:<-[-]"
uncompressing rx.el.gz...done
Mark saved where search started
Mark set
Quit
rx-any
Undo! [5 times]
Quit

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message dired dired-loaddefs format-spec
rfc822 mml mml-sec password-cache epa derived epg epg-config gnus-util
rmail rmail-loaddefs mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils misearch multi-isearch jka-compr thingatpt
find-func cl-macs gv rx help-mode easymenu cl-loaddefs pcase cl-lib
debug time-date mule-util tooltip eldoc electric uniquify ediff-hook
vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd
tool-bar dnd fontset image regexp-opt fringe tabulated-list newcomment
elisp-mode lisp-mode prog-mode register page menu-bar rfn-eshadow timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame cl-generic cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932
hebrew greek romanian slovak czech european ethiopic indian cyrillic
chinese charscript case-table epa-hook jka-cmpr-hook help simple abbrev
obarray minibuffer cl-preloaded nadvice loaddefs button faces cus-face
macroexp files text-properties overlay sha1 md5 base64 format env
code-pages mule custom widget hashtable-print-readable backquote
dbusbind inotify dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 98843 7545)
 (symbols 48 20526 0)
 (miscs 40 66 232)
 (strings 32 17396 4397)
 (string-bytes 1 516394)
 (vectors 16 13017)
 (vector-slots 8 436246 5148)
 (floats 8 167 222)
 (intervals 56 1138 261)
 (buffers 976 13)
 (heap 1024 27331 958))

-- 
Patrick Xarles Hayes