bug#20440: reproducible recipe

I use Ubuntu 15.04.
I can reproduce this both in Emacs 24.4
which is installed by "apt-get install emacs24"
and in Emacs 24.5 which I built from the source.

The corrupted buffer looks like this.
https://gist.github.com/stakemori/8c3e1f6e3f73f5db3a7a

The output of M-x report-emacs-bug in Emacs 24.4 is as follows:

From: sho <sho@K430-Ubuntu.i-did-not-set--mail-host-address--so-tickle-me>

To: bug-gnu-emacs@gnu.org

Subject: 24.4; revert-buffer

--text follows this line--

In GNU Emacs 24.4.1 (x86_64-pc-linux-gnu, GTK+ Version 3.14.9)

of 2015-03-21 on kissel, modified by Debian

Windowing system distributor `The X.Org Foundation', version 11.0.11701000

System Description: Ubuntu 15.04

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,-Bsymbolic-functions -Wl,-z,relro''

Important settings:

value of $LANG: ja_JP.UTF-8

value of $XMODIFIERS: @im=fcitx

locale-coding-system: utf-8-unix

Major mode: Python

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-y M-x e v a l 0 <backspace> - b u <tab> <return>

M-x r e p o r t - e m a c s <tab> <return>

Recent messages:

For information about GNU Emacs and the GNU system, type C-h C-a.

Mark set

Can't guess python-indent-offset, using defaults: 4 [2 times]

or: Assertion failed: (string= (buffer-string) file-content2)

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

help-fns mail-prsvr mail-utils python easymenu json comint ring

ansi-color cl-macs gv cl-loaddefs cl-lib time-date japan-util 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 82225 4373)

(symbols 48 18572 0)

(miscs 40 40 99)

(strings 32 12434 4244)

(string-bytes 1 367042)

(vectors 16 11207)

(vector-slots 8 474430 27975)

(floats 8 64 67)

(intervals 56 262 1)

(buffers 960 13)

(heap 1024 25157 1072))

From:	Sho Takemori
Subject:	bug#20440: reproducible recipe
Date:	Fri, 11 Sep 2015 13:08:11 +0900