bug#23294: 25.0.92; modify-file-local-variable-prop-line adds extra "; "

[Mohammed Sadik P. K.]

For the function modify-file-local-variable-prop-line if run with
'add-or-replace as the third argument, it should replace the current
values. It does, but along with replacing the values, it adds an extra "; " at
the beginning of the variable.

Eg.:

my current first line:
   /* -*- mode: c; indent-tabs-mode: t; -*- */

I executed (modify-file-local-variable-prop-line 'indent-tabs-mode 'nil
'add-or-replace)

The result was:

   /* -*- mode: c; ; indent-tabs-mode: nil; -*- */

Expected result:

   /* -*- mode: c; indent-tabs-mode: nil; -*- */

Each time I run the function, an "; " is added.



In GNU Emacs 25.0.92.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.18.9)
 of 2016-04-13 built on fedora.localdomain
Windowing system distributor 'Fedora Project', version 11.0.11800000
Configured features:
XPM JPEG TIFF GIF PNG SOUND DBUS GSETTINGS NOTIFY ACL LIBSELINUX GNUTLS
LIBXML2 FREETYPE XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LC_MONETARY: en_IN.UTF-8
  value of $LC_NUMERIC: en_IN.UTF-8
  value of $LC_TIME: en_IN.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: C/l

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-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
  abbrev-mode: t

Recent messages:
Undo!
(No changes need to be saved)
For this change to take effect revisit file using M-x revert-buffer
Saving file /home/sadiq/test.c...
Wrote /home/sadiq/test.c
Making completion list... [2 times]
nil
Saving file /home/sadiq/test.c...
Wrote /home/sadiq/test.c
Making completion list...

Load-path shadows:
None found.

Features:
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mml-sec epg epg-config gnus-util mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils thingatpt help-fns
debug files-x cl-extra help-mode cc-mode cc-fonts easymenu cc-guess
cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars cc-defs
cl-loaddefs pcase cl-lib time-date mule-util tooltip eldoc electric
uniquify ediff-hook vc-hooks lisp-float-type mwheel x-win
term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list newcomment elisp-mode lisp-mode prog-mode register page
menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core frame cl-generic cham georgian utf-8-lang
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simple abbrev minibuffer cl-preloaded 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
dbusbind inotify dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 107079 7193)
 (symbols 48 21723 0)
 (miscs 40 82 182)
 (strings 32 20174 4378)
 (string-bytes 1 689608)
 (vectors 16 14280)
 (vector-slots 8 449743 7625)
 (floats 8 168 213)
 (intervals 56 281 16)
 (buffers 976 14)
 (heap 1024 54266 1231))