bug#29254: 24.4; Unexpected case-folding in occur when case-fold-search set

[Fran Burstall]

>From emacs -Q:

Put the following text in a buffer:

MA
ma
MA
ma

Do M-x set-variable to set case-fold-search to t (buffer-locally).

Do M-s o to call occur with regexp "MA".

I expect: 2 lines in the *Occur* buffer matching the MA lines

I get: 4 lines matching all occurrences of the string
regardless of case.

I get the expected (documented) behaviour if I do not
explicitly set case-fold-search to t.

Commentary: the problem is in occur-engine.  This correctly sets
case-fold-search to nil at the start of the function but that seems to get
overridden by the time the actual search happens inside the
with-current-buffer clause.  Some weird scope thing with
buffer-local variables?

---Fran







In GNU Emacs 24.4.1 (x86_64-pc-linux-gnu, GTK+ Version 3.14.5)
 of 2017-09-12 on hullmann, modified by Debian
Windowing system distributor `The X.Org Foundation', version 11.0.11604000
System Description:     LMDE 2 Betsy

Configured using:
 `configure --build x86_64-linux-gnu --prefix=/usr
 --sharedstatedir=/var/lib --libexecdir=/usr/lib
 --localstatedir=/var/lib --infodir=/usr/share/info
 --mandir=/usr/share/man --with-pop=yes
 
--enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.4/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.4/site-lisp:/usr/share/emacs/site-lisp
 --build x86_64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib
 --libexecdir=/usr/lib --localstatedir=/var/lib
 --infodir=/usr/share/info --mandir=/usr/share/man --with-pop=yes
 
--enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.4/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.4/site-lisp:/usr/share/emacs/site-lisp
 --with-x=yes --with-x-toolkit=gtk3 --with-toolkit-scroll-bars
 'CFLAGS=-g -O2 -fstack-protector-strong -Wformat
 -Werror=format-security -Wall' CPPFLAGS=-D_FORTIFY_SOURCE=2
 LDFLAGS=-Wl,-z,relro'

Important settings:
  value of $LANG: en_GB.utf8
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-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 input:
C-h v c a s e - f o l d - s e <tab> <return> M A <return> 
m a <return> M A <return> m a <return> M-s o M A <return> 
M-x s e t - v a r i a b l e <return> c a s e - f o 
l d - s e a r <tab> <return> t <return> M-s o <return> 
M-x r e p o r t <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Type C-x 1 to delete the help window.
Searched 1 buffer; 2 matches for `MA'
Searched 1 buffer; 4 matches for `MA'

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils cus-edit wid-edit cl-loaddefs cl-lib cus-start
cus-load help-mode easymenu help-fns time-date tooltip electric uniquify
ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd
fontset image regexp-opt fringe tabulated-list newcomment lisp-mode
prog-mode register page menu-bar rfn-eshadow timer select scroll-bar
mouse jit-lock font-lock syntax facemenu font-core frame cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev
minibuffer 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 make-network-process
dbusbind gfilenotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)

Memory information:
((conses 16 91794 4676)
 (symbols 48 19365 0)
 (miscs 40 46 124)
 (strings 32 13753 3607)
 (string-bytes 1 373062)
 (vectors 16 10107)
 (vector-slots 8 393223 8222)
 (floats 8 73 294)
 (intervals 56 261 19)
 (buffers 960 13)
 (heap 1024 23656 1037))
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