bug#19088: 24.3; rmail-summary-by-regexp only searches the raw Subject: header

[Dale R. Worley]

rmail-summary-by-regexp searches the headers of the messages in an
Rmail buffer and displays those that contain a header that matches the
user-provided regexp.  However, in regard to the Subject: header, the
search is done against the "raw" header, not against the string after
encoded-words (=?...?= constructions) are processed.  Given that in
all situations (other than when rmail-mime is in effect), Rmail shows
the decoded Subject: rather than the raw header, the search can easily
not find messages that the user expects to match.  In extreme cases,
the user can copy the text of a message's Subject: header for use as
the argument to rmail-summary-by-regexp but no messages will be
reported in the RMAIL-summary buffer.

To demonstrate this, put one message in a mailbox file and replace its
Subject: line with:

    Subject: 
=?UTF-8?Q?Re=3A_=5Bgit=2Dusers=5D_Re=3A_git_1=2E9=2E4=E2=80=8F_for_window_prompt_s?=
            =?UTF-8?Q?h=2Eexe=3A_=2Fdev=2Fnull_No_such_file_or_dirctory?=

this decodes to:

    Subject: Re: [git-users] Re: git 1.9.4‏ for window prompt sh.exe: /dev/null 
No such file or dirctory

Now execute:

    C-M-s /dev/null RET

The user will expect to see the one message listed in the
RMAIL-summary buffer.  But it will not be.



In GNU Emacs 24.3.1 (x86_64-redhat-linux-gnu, GTK+ Version 3.8.2)
 of 2013-08-14 on buildvm-15.phx2.fedoraproject.org
Windowing system distributor `Fedora Project', version 11.0.11404000
System Description:     Fedora release 19 (Schrödinger’s Cat)

Configured using:
 `configure '--build=x86_64-redhat-linux-gnu'
 '--host=x86_64-redhat-linux-gnu' '--program-prefix='
 '--disable-dependency-tracking' '--prefix=/usr' '--exec-prefix=/usr'
 '--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc'
 '--datadir=/usr/share' '--includedir=/usr/include'
 '--libdir=/usr/lib64' '--libexecdir=/usr/libexec'
 '--localstatedir=/var' '--sharedstatedir=/var/lib'
 '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--with-dbus'
 '--with-gif' '--with-jpeg' '--with-png' '--with-rsvg' '--with-tiff'
 '--with-xft' '--with-xpm' '--with-x-toolkit=gtk3' '--with-gpm=no'
 'build_alias=x86_64-redhat-linux-gnu'
 'host_alias=x86_64-redhat-linux-gnu' 'CFLAGS=-DMAIL_USE_LOCKF -O2 -g
 -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector
 --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic'
 'LDFLAGS=-Wl,-z,relro ''

Important settings:
  value of $LC_COLLATE: C
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Apropos

Minor modes in effect:
  shell-dirtrack-mode: t
  mouse-wheel-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

Recent input:
<help-echo> <help-echo> <help-echo> C-x b t e m p <return> 
* ! g C-p C-p C-p o M-< M-> C-x o C-p o M-< M-> C-x 
o C-p C-p o M-< M-> C-x o C-x b R M <tab> <return> 
t C-x 1 C-s s u b j e c t C-s C-s C-a C-x 2 C-x o C-x 
b M-| C-x I R M <tab> <return> y C-x o C-p C-p C-p 
M-f M-f M-f M-b C-s C-w C-w C-w C-w C-w <return> C-x 
o M-> C-r C-r C-a M-v M-v M-v M-v C-u C-p C-p C-p C-p 
C-p C-n C-SPC C-M-s f r o m SPC C-s C-s C-s C-s C-a 
C-x C-x C-M-s ^ f r o m SPC C-s C-a M-w C-x C-f ~ / 
t e m p / R 1 <tab> <return> <return> C-y M-< C-x C-b 
C-x o C-n f C-x n w M-> C-x 0 C-s s u b j e c t : SPC 
C-a M-> M-< C-x C-s <help-echo> C-s g i t SPC f o r 
SPC w i n d C-a C-n C-n C-n M-x b u g <tab> C-g C-x 
<escape> <escape> M-p M-p M-p M-p M-p M-p M-p M-p M-p 
M-p M-p M-p M-n M-p M-p M-p M-p M-p M-p M-p M-p M-p 
M-p M-p M-p M-p M-p M-p M-p M-p M-p M-p M-p M-p M-p 
M-p M-p M-p M-p M-p M-p M-p M-p M-p M-p M-p C-g M-x 
s u b m <tab> C-g M-x a p r o p o s C-g C-h a b u g 
<return> C-x o C-n C-n C-n C-n C-n C-n C-n C-n C-M-s 
\ < b u g \ > C-s C-s C-s C-s C-s C-s C-a C-l M-x r 
e m <backspace> p o r <tab> <return>

Recent messages:
Mark saved where search started
Mark set [2 times]
Saving file /home/worley/temp/R1...
Wrote /home/worley/temp/R1
Mark saved where search started
Quit
user-error: Beginning of history; no preceding item [14 times]
Quit [3 times]
Type C-x 1 to remove help window.  
Mark saved where search started

Load-path shadows:
None found.

Features:
(apropos mail-extr timezone rmailsort shadow emacsbug vc-git rect
pcmpl-linux pp wid-edit descr-text doc-view jka-compr image-mode
vc-dispatcher vc-svn pcmpl-gnu tar-mode sgml-mode rmailkwd compare-w
arc-mode archive-mode edmacro two-column kmacro iso-transl etags
tramp-cache tramp-sh tramp warnings tramp-compat auth-source eieio
byte-opt bytecomp byte-compile cconv gnus-util password-cache
tramp-loaddefs cl-macs gv advice help-fns advice-preload rmailedit
rmailout cookie1 pcmpl-unix teco perl-mode sh-script smie executable
conf-mode tabify ispell ebuff-menu electric mule-util help-mode qp
rmailsum rmailmm rmail cl cl-lib message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader mailalias sendmail rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils man shell pcomplete comint
ansi-color ring misearch multi-isearch dired-aux dired time-date
tooltip 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 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 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 dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty emacs)