23.0.60; M-x occur no longer uses previous regexp as default

[Sven Joachim]

In Emacs 22, M-x occur uses the previous regexp as default when invoked
a second time, so you could just press RET to look for it again.  Now
you have to use M-p to receive the previous regexp, if you forget that
Emacs hangs and uses 100% CPU (interruptible with C-g, backtrace
follows):

,----
| Debugger entered--Lisp error: (quit)
|   string-match("" #("To: address@hidden" 0 2 (fontified t face 
message-header-name auto-composed t) 2 3 (fontified t face message-header-name 
auto-composed t) 3 4 (fontified t auto-composed t) 4 29 (fontified t face 
message-header-to auto-composed t)) 0)
|   occur-engine("" (#<buffer *mail to address@hidden>) #<buffer *Occur*> 0 t 
underline nil match t)
|   occur-1("" nil (#<buffer *mail to address@hidden>))
|   occur("" nil)
|   call-interactively(occur nil nil)
`----

FWIW, Emacs 22 directly signals an error if you supply an empty string
in M-x occur.


In GNU Emacs 23.0.60.1 (i486-pc-linux-gnu, GTK+ Version 2.12.9)
 of 2008-04-18 on debian, modified by Debian
 (emacs-snapshot package, version 1:20080416-3)
Windowing system distributor `The X.Org Foundation', version 11.0.10300000
configured using `configure  '--build' 'i486-linux-gnu' '--host' 
'i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' 
'--libexecdir=/usr/lib' '--localstatedir=/var' '--infodir=/usr/share/info' 
'--mandir=/usr/share/man' '--with-pop=yes' 
'--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/23.0.60/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.0.60/site-lisp:/usr/share/emacs/site-lisp'
 '--with-x=yes' '--with-x-toolkit=gtk' '--disable-font-backend' 
'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN 
-DSITELOAD_PURESIZE_EXTRA=5000 -g -O2''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: C
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: de_DE.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Log-View

Minor modes in effect:
  shell-dirtrack-mode: t
  display-time-mode: t
  auto-image-file-mode: t
  show-paren-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-compression-mode: t
  temp-buffer-resize-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<right> <right> <right> <right> <right> SPC <f9> <delete> 
<right> <right> <right> <right> <right> <right> <right> 
<right> <right> <right> <right> <right> <right> SPC 
<f9> <delete> <right> <right> <right> <right> <right> 
<right> <right> <right> <right> <right> <right> <right> 
<right> <right> <right> <right> <delete> SPC SPC <f9> 
<delete> <right> <right> <right> <right> <right> <right> 
<right> <right> <right> SPC <f9> <delete> <right> <right> 
<right> <right> <right> <right> <right> <right> <right> 
SPC <f9> <delete> <right> <right> <right> <right> <right> 
<right> <right> <right> <right> SPC <f9> <delete> <right> 
<right> <right> <right> <right> <right> <right> <right> 
<right> <right> <right> SPC <f9> <delete> <right> <right> 
<right> <right> <right> <right> <right> <right> <right> 
<right> SPC <f9> C-c C-c o C-z C-c o <up> <return> 
C-x 1 C-x C-s C-c <return> C-x <return> f i s o <tab> 
l <tab> 1 - u <tab> <return> C-x C-s C-x C-j g <down> 
<down> <down> y <up> <up> <up> <return> C-x k <return> 
C e l o a p r 0 8 <return> <return> C-x d / u s r <tab> 
l o c <tab> s r <tab> t r <tab> e <tab> l i s <tab> 
<return> C-s o c c u r r <return> <C-end> C-c o o c 
c u r <return> C-c l o c c u r <return> C-h k C-c o 
C-x o <tab> <return> C-x 1 C-x C-j C-c l <return> <next> 
<prior> <next> <prior> <up> <up> <return> C-x b <return> 
q C-x 4 n C-c C-b C-x C-b C-x o <down> d d x <up> g 
<return> C-x 1 C-x v l C-s o c c u r C-s C-s C-s C-s 
C-s C-s C-s C-s C-s C-s C-s C-s C-s C-s C-s C-s C-x 
1 <next> <f8> C-g M-x r e p o <tab> r t - e m <tab> 
<return> b <return>

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