bug#12437: 24.2; Edits to buffer does not get written to the file (Issue Does not happen in 23.x version)

[Vishwajith Singh]

Issue: 24.2; Edits to buffer does not get written to the file whereas
the same file can be edited in emacs-23.3 without issues.

Here's what happens -

emacs 24.2
==========
1) Open a file with permissions "-rwxrwxrwx".
        The modeline shows "---" indicating that the file is writable.
2) Edit the file
        The modeline show "**-"
3) Save the file...
        The modebuffer shows "Saving file..."
        The modeline still shows "**-"
3)  Now try quitting the buffer.
       The modeline shows "Changes made to the file, quit anyway..."
   Strange message since the changes were saved in step 2.
   If you quit, the changes  are lost.

emacs 23.x
==========
1) OPen the same file in older emacs 23.X version and go thourgh the
same steps. No issues and the changes are savsed and the buffer can be
quit...

Why is this happening in 24.2?


==================================================================
In GNU Emacs 24.2.1 (x86_64-unknown-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2012-09-11 on lca-700s
Windowing system distributor `Hummingbird - Open Text', version 11.0.13800
Configured using:
 `configure '--prefix=/usr/local/emacs-24.2''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  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: C
  value of $XMODIFIERS: nil
  locale-coding-system: nil
  default enable-multibyte-characters: t

Major mode: Shell

Minor modes in effect:
  dirtrack-mode: t
  show-paren-mode: t
  shell-dirtrack-mode: t
  recentf-mode: t
  tooltip-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
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<left> <left> <left> <left> <left> <left> <left> <left>
<left> <left> <left> <left> <left> <left> <left> <left>
<backspace> 9 C-s C-s C-s C-s C-x C-s M-k C-g C-x C-s
M-k y l s SPC - l SPC <return> c d SPC - <return> l
s SPC - l SPC <return> c d SPC - <return> C-x <escape>
<escape> <return> <return> C-x C-s M-k y l s SPC -
l SPC h s <tab> s <tab> <return> l s SPC - a l <return>
C-x C-f h s _ a s <tab> <return> C-s C-s C-s <left>
<left> <left> <left> <left> <left> <left> <left> <left>
<left> <left> <left> <left> <left> <left> <left> <left>
<left> <left> <left> <left> <left> <left> <left> <left>
<left> <backspace> 9 C-x C-s M-k y <help-echo> <help-echo>
<down-mouse-1> <mouse-1> <down-mouse-1> <mouse-1> <down-mouse-5>
<mouse-5> <double-down-mouse-5> <double-mouse-5> <triple-down-mouse-5>
<triple-mouse-5> <triple-down-mouse-5> <triple-mouse-5>
<triple-down-mouse-5> <triple-mouse-5> <down-mouse-5>
<mouse-5> <down-mouse-1> <mouse-1> w h i c h SPC e
m a c s <return> n e d i t SPC h s <tab> a a <backspace>
<tab> <return> <down-mouse-1> <mouse-1> C-s C-s C-x
C-f M-p <return> C-s C-s C-s C-s C-x C-s <return> <backspace>
<return> C-x C-s M-k <backspace> <down-mouse-1> <mouse-1>
<down-mouse-1> <mouse-movement> <mouse-1> M-k y <f11>
<f12> e <backspace> a SPC | SPC g r e p SPC e m a c
s <return> <down-mouse-1> <mouse-movement> <mouse-1>
$ E M A S <backspace> C S _ O L D <return> <down-mouse-1>
<mouse-1> M-x r e p o <tab> r t <tab> - <tab> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <tab> <tab> <tab>
<tab> <tab> <tab> <tab> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<backspace> <backspace> <backspace> <backspace> <backspace>
<tab> <tab> <return>

Recent messages:
Buffer hs_async_scheduler.v modified; kill anyway? (y or n)  y
scroll-up: End of buffer
Mark saved where search started [2 times]
(No changes need to be saved)
Saving file 
/proj/sycmr0/wa/vsingh/tmp/vault/ip_design/usb3_host_core/August_6_2012/mrvl_host_vpp/asic_release/src/xhci/transaction_scheduler/hs_async_scheduler.v...
Buffer hs_async_scheduler.v modified; kill anyway? (y or n)  n
Buffer hs_async_scheduler.v modified; kill anyway? (y or n)  y
Mark set
/proj/sycmr0/wa/vsingh/tmp/vault/ip_design/usb3_host_core/August_6_2012/mrvl_host_vpp/asic_release/src/xhci/transaction_scheduler
Making completion list... [2 times]

Load-path shadows:
None found.

Features:
(shadow mail-extr emacsbug message rfc822 mml mml-sec mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mail-utils executable tabify
verilog-mode skeleton compile diff ffap misearch multi-isearch make-mode
help-mode view pcmpl-unix autoinsert sunrise-commander tramp
tramp-compat auth-source eieio assoc gnus-util mm-util mail-prsvr
password-cache format-spec tramp-loaddefs esh-var esh-io esh-cmd esh-ext
esh-proc esh-arg eldoc esh-groups eshell esh-util esh-module esh-mode
dired-aux desktop term ehelp electric sort hl-line find-dired disp-table
enriched dired-x dired derived jka-compr protbuf dirtrack vc-hg linum
paren cus-start cus-load ediff-trees ediff-merg ediff-diff ediff-wind
ediff-help ediff-util ediff-mult ediff-init ediff breadcrumb byte-opt
warnings bytecomp byte-compile cconv macroexp shell-command shell
pcomplete comint regexp-opt ansi-color ring column-marker color-theme cl
recentf tree-widget wid-edit easymenu tabbar easy-mmode hide-lines
hide-region advice help-fns advice-preload setnu ibs edmacro kmacro
time-date tooltip ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd
tool-bar dnd fontset image fringe 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 files text-properties overlay sha1 md5 base64 format env
code-pages mule custom widget hashtable-print-readable backquote
make-network-process dynamic-setting font-render-setting x-toolkit x
multi-tty emacs)