bug#13891: 24.3.50; highlight-regexp incorrectly retains partial state after buffer reversion

[Jambunathan K <kjambunathan@gmail.com>]

I can circulate a patch for some or all of what you report below. Are
you willing to apply the patch and give immediate feedback?  Please
confirm with Yes or No.

Josh <josh@foxtail.org> writes:

> I noticed two things that show that partial highlight-regexp state
> lingers after calling revert-buffer, see items 9 and 12.  After buffer
> reversion, I would expect this state either to be completely backed
> out or to survive completely intact.  Ideally both of these behaviors
> would be supported and under users' control.
>
>  (1) emacs -Q foo.txt
>  (2) insert `foo bar' into buffer and save
>  (3) M-s h r foo RET RET
>  (4) note that foo is highlighted with hi-yellow face
>  (5) make a trivial edit to make buffer-modified-p be true
>  (6) M-x revert-buffer and confirm
>  (7) note that highlighting goes away as expected
>  (8) M-s h r bar RET but do not respond to the prompt for the face
>  (9) Expected default face: hi-yellow.  Actual: hi-pink.
> (10) C-g to cancel the highlight-regexp command
> (11) M-s h u but do not respond to the prompt for a regexp
> (12) Expected: "No highlighting to remove".  Actual: prompts for
> regexp with a default of foo.
> (13) Hit RET to accept the default regexp foo to unhighlight
> (14) M-s h u
> (15) note that "No highlighting to remove" appears, as should have
> happened after (11)
>
> In GNU Emacs 24.3.50.1 (x86_64-apple-darwin, NS apple-appkit-1187.34)
>  of 2013-03-04 on bix
> Bzr revision: 111935 yamaoka@jpl.org-20130304102733-4qy111z41qwoh2as
> Windowing system distributor `Apple', version 10.3.1187
> Configured using:
>  `configure --host=x86_64-apple-darwin --build=i686-apple-darwin
>  --with-ns'
>
> Important settings:
>   value of $LC_CTYPE: en_US.UTF-8
>   value of $LANG: en_US.UTF-8
>   locale-coding-system: utf-8-unix
>   default enable-multibyte-characters: t
>
> Major mode: Text
>
> Minor modes in effect:
>   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
>   line-number-mode: t
>   transient-mark-mode: t
>
> Recent input:
> f o o SPC f a <backspace> <backspace> b a r C-x C-s
> M-s h r f o o <return> <return> SPC M-x r e v e r t
> - b u f f <tab> <return> y e s <return> M-s h r b a
> r <return> C-g M-s h u <return> M-s h u M-x e <backspace>
> r e p o r t - e m a c s - b u f <tab> <return> <backspace>
> <return> h i g h l i g h t - r e g e x p SPC i n c
> o r r e c t l y SPC r e t a i n s SPC s t a t e SPC
> a f t e r SPC b u f f e r SPC r e v e r s i o n C-a
> C-k C-g M-x r e p o r t - e m a c s - b u g <retur
> n>
>
> Recent messages:
> For information about GNU Emacs and the GNU system, type C-h C-a.
> foo.txt has auto save data; consider M-x recover-this-file
> Saving file /Users/jlf/tmp/foo.txt...
> Wrote /Users/jlf/tmp/foo.txt
> You can run the command `revert-buffer' with s-u
> Quit
> byte-code: No highlighting to remove
> Quit
>
> Load-path shadows:
> None found.
>
> Features:
> (shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
> easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
> mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
> mm-util mail-prsvr mail-utils hi-lock time-date tooltip ediff-hook
> vc-hooks lisp-float-type mwheel ns-win tool-bar dnd fontset image
> regexp-opt fringe tabulated-list newcomment 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 macroexp files text-properties overlay sha1 md5
> base64 format env code-pages mule custom widget hashtable-print-readable
> backquote make-network-process ns multi-tty emacs)
>
>
>
>

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