--text follows this line-- Please write in English if possible, because the Emacs maintainers usually do not have translators to read other languages for them. Your bug report will be posted to the emacs-pretest-bug@gnu.org mailing list. Please describe exactly what actions triggered the bug and the precise symptoms of the bug: In 34.3.1.3 Backslash Constructs in Regular Expressions of Emacs Lisp Reference , If a particular grouping construct in the regular expression was never matched--for instance, if it appears inside of an alternative that wasn't used, or inside of a repetition that repeated zero times--then the corresponding `\DIGIT' construct never matches anything. To use an artificial example,, `$foo\(b*$\|lose\)\2' cannot match `lose': the second alternative inside the larger group matches it, but then `\2' is undefined and can't match anything. But it can match `foobb', because the first alternative matches `foob' and `\2' matches `b'. After "To use an artificial example" , there are two commas . PS. why can I not send bug in emacs ? it says :Sending...failed with exit value 1 Thanks If Emacs crashed, and you have the Emacs process in the gdb debugger, please include the output from the following gdb commands: `bt full' and `xbacktrace'. If you would like to further debug the crash, please read the file /usr/share/emacs/23.0.96/etc/DEBUG for instructions. In GNU Emacs 23.0.96.1 (i686-pc-linux-gnu, GTK+ Version 2.16.1) of 2009-07-09 on laptop Windowing system distributor `The X.Org Foundation', version 11.0.10503000 configured using `configure '--prefix=/usr' '--build=i686-pc-linux-gnu' '--host=i686-pc-linux-gnu' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--datadir=/usr/share' '--sysconfdir=/etc' '--localstatedir=/var/lib' '--program-suffix=-emacs-23' '--infodir=/usr/share/info/emacs-23' '--with-sound' '--with-x' '--without-toolkit-scroll-bars' '--with-gif' '--with-jpeg' '--with-png' '--with-rsvg' '--with-tiff' '--with-xpm' '--with-xft' '--without-libotf' '--without-m17n-flt' '--with-x-toolkit=gtk' '--without-hesiod' '--without-kerberos' '--without-kerberos5' '--with-gpm' '--with-dbus' 'build_alias=i686-pc-linux-gnu' 'host_alias=i686-pc-linux-gnu' 'CFLAGS=-O2 -march=pentium-m -pipe' 'LDFLAGS=-Wl,-O1'' Important settings: value of $LC_ALL: nil value of $LC_COLLATE: en_US.UTF-8 value of $LC_CTYPE: zh_CN.UTF-8 value of $LC_MESSAGES: en_US.UTF-8 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=SCIM locale-coding-system: utf-8-unix default-enable-multibyte-characters: t Major mode: Info Minor modes in effect: show-paren-mode: t display-time-mode: t global-auto-complete-mode: t desktop-save-mode: t yas/minor-mode: t auto-image-file-mode: t shell-dirtrack-mode: t tooltip-mode: t tool-bar-mode: t mouse-wheel-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t global-auto-composition-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t column-number-mode: t line-number-mode: t transient-mark-mode: t abbrev-mode: t Recent input:

C-x 1

Recent messages: bunzip2ing elisp-7.info.bz2...done goto-history-element: Beginning of history; no preceding item [7 times] 200 matches (limit reached) [2 times] byte-code: End of buffer Mark set No matches [6 times] byte-code: End of buffer [5 times] bunzip2ing elisp-8.info.bz2...done byte-code: End of buffer [2 times] bunzip2ing elisp-7.info.bz2...done