bug#21277: 25.0.50; char-fold search is a screw, and I can't see how to disable

[Richard Stallman <rms@gnu.org>]

1. Char-fold isearch is a screw.  I wanted to search for lines
starting with a space, so I searched for C-j SPC, but it did something
useless.  It found every blank line!

2. So I decided to try to disable it, but the doc string of
isearch says nothing about how to turn that off.  It should say how.

3. I tried using C-h v to find a variable, but although there is
isearch-case-fold-search, there is no isearch-char-fold-search.
For parallelism's sake, isearch-char-fold-search should exist.

4. I searched in etc/NEWS for 'char fold' and 'char-fold'.
Neither appears.  Both of them SHOULD appear, for the sake
of people who search for them.

5. I did find 'isearch', and that entry described the new inconvenient
feature.  However the entry there did not say how to disable this
feature.  It should say how.




In GNU Emacs 25.0.50.1 (i686-pc-linux-gnu, GTK+ Version 2.24.23)
 of 2015-08-12 on freetop
Repository revision: 79a169684dfad2c0bbb9fdbae539c1f30d9f0ac3
System Description:	Trisquel GNU/Linux 7.0, Belenos

Configured using:
 `configure 'CFLAGS=-g -O0''

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

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Help

Minor modes in effect:
  diff-auto-refine-mode: t
  shell-dirtrack-mode: t
  gpm-mouse-mode: t
  tooltip-mode: t
  global-eldoc-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
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t

Recent messages:
Mark set
Mark saved where search started [7 times]
Quit
Type C-x 1 to delete the help window, C-M-v to scroll help.
Mark saved where search started [2 times]
Auto-saving...
Mark saved where search started
Making completion list...
Quit
C-x 4 C-g is undefined

Load-path shadows:
None found.

Features:
(eieio-opt speedbar sb-image ezimage dframe find-func novice vc
vc-dispatcher vc-git bug-reference add-log pp shadow emacsbug
parse-time vc-cvs etags thingatpt xref project cal-move cal-menu
calendar cal-loaddefs wid-edit battery sgml-mode epa-file rmailkwd
ispell epa-mail epa derived epg diff-mode easy-mmode diff dired-aux
sh-script smie executable quail rmailsum conf-mode rmailout shr-color
color url-util url-parse auth-source cl-seq eieio byte-opt bytecomp
byte-compile cl-extra seq cconv eieio-core cl-macs gv gnus-util
password-cache url-vars shr dom subr-x browse-url misearch
multi-isearch dabbrev shell pcomplete grep compile comint ansi-color
ring mailalias qp rmailmm message sendmail format-spec rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mailabbrev gmm-utils mailheader
mail-parse rfc2231 rmail rfc2047 rfc2045 ietf-drums mm-util help-fns
help-mode cl-loaddefs pcase cl-lib mail-prsvr mail-utils dired t-mouse
view time-date paren cus-start cus-load advice finder-inf package
easymenu epg-config mule-util tooltip eldoc electric uniquify
ediff-hook vc-hooks lisp-float-type mwheel 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 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 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 gfilenotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty
make-network-process emacs)

Memory information:
((conses 8 387608 101135)
 (symbols 24 28231 3)
 (miscs 20 5511 4232)
 (strings 16 51815 17926)
 (string-bytes 1 1899171)
 (vectors 8 31455)
 (vector-slots 4 1538023 39042)
 (floats 8 453 880)
 (intervals 28 70732 2674)
 (buffers 520 156)
 (heap 1024 23258 2927))
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[[[ whether defending the US Constitution against all enemies,     ]]]
[[[ foreign or domestic, requires you to follow Snowden's example. ]]]


-- 
Dr Richard Stallman
President, Free Software Foundation (gnu.org, fsf.org)
Internet Hall-of-Famer (internethalloffame.org)
Skype: No way! See stallman.org/skype.html.