bug#10405: 24.0.92; XML parser -- problem handling comments

[Michael Albinus]

Hi Mark,

I don't know whether you still care about xml.el. If yes, yould you
please go through this bug report? For my eyes, the proposed patch from
Alex looks OK, but you might know it better.

Thanks, and best regards, Michael.

Alex Harsanyi <harsanyi@mac.com> writes:

> There seems to be a bug in `xml-parse-tag' when handling comments.  To
> reproduce it, create a buffer containing the following text on a single line:
>
>     <!-- hello --><outer><inner></inner></outer>
>
> Trying to parse this using 
>
>    M-: (xml-parse-region (point-min) (point-max)) 
>
> will return:
>
>    ((inner nil))
>
> instead of:
>
>    ((outer nil (inner nil)))
>
> Inserting a space or newline after the end comment tag (-->) seems to
> avoid this bug.
>
> The patch below fixes the problem, but I'm not sure if it is the correct
> fix (I just copied the code from the part that handles processing
> instructions, that start with <?):
>
> === modified file 'lisp/xml.el'
> *** lisp/xml.el       2011-11-20 03:48:53 +0000
> --- lisp/xml.el       2011-12-30 00:39:42 +0000
> ***************
> *** 421,427 ****
>        ;;  skip comments
>        ((looking-at "<!--")
>         (search-forward "-->")
> !       nil)
>        ;;  end tag
>        ((looking-at "</")
>         '())
> --- 421,428 ----
>        ;;  skip comments
>        ((looking-at "<!--")
>         (search-forward "-->")
> !       (skip-syntax-forward " ")
> !       (xml-parse-tag parse-dtd xml-ns))
>        ;;  end tag
>        ((looking-at "</")
>         '())
>
>
>
>
> In GNU Emacs 24.0.92.1 (x86_64-apple-darwin10.8.0, NS apple-appkit-1038.36)
> of 2011-12-30 on karinji-2.local
> Windowing system distributor `Apple', version 10.3.1038
> configured using `configure  '--with-ns''
>
> 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: en_AU.UTF-8
>   value of $XMODIFIERS: nil
>   locale-coding-system: utf-8-unix
>   default enable-multibyte-characters: t
>
> Major mode: Fundamental
>
> 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
>   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-x b * x m l * <return> < ! - - SPC h e l l o SPC 
> - - > < o u t e r > < i n n e r > < / i n n e r > / 
> <backspace> < / o u t e r > <return> <up> s-: s-( s-: 
> s-: M-: e <backspace> x <backspace> ( x m o <backspace> 
> l - p a s e <backspace> <backspace> r s e - r e g i 
> o n SPC ( p o i n t - m i n ) SPC ( p o i n t ) <backspace> 
> - m a x ) ) <return> <right> <right> <right> <right> 
> <right> <right> <right> <right> <right> <right> <right> 
> <right> <right> <right> <return> M-: <up> <return> 
> <backspace> SPC M-: <up> <return> <right> <left> <backspace> 
> M-: <down> <up> <return> <left> <right> <right> <right> 
> <right> <right> <right> <right> <right> M-x r e p o 
> <tab> r t <tab> <return>
>
> Recent messages:
> For information about GNU Emacs and the GNU system, type C-h C-a.
> Starting new Ispell process [default] ...
> Spell-checking *xml* using aspell with default dictionary...done
> Spell-checking *xml* using aspell with default dictionary...done
> Spell-checking *xml* using aspell with default dictionary...done
> ((inner nil))
> ((outer nil (inner nil))) [2 times]
> goto-history-element: End of history; no default available
> ((inner nil))
> Making completion list...
>
> Load-path shadows:
> None found.
>
> Features:
> (shadow sort gnus-util mail-extr message format-spec rfc822 mml mml-sec
> mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045
> ietf-drums mm-util mail-prsvr mailabbrev mail-utils gmm-utils mailheader
> emacsbug help-mode easymenu view xml regexp-opt ispell time-date tooltip
> ediff-hook vc-hooks lisp-float-type mwheel ns-win 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 dbusbind ns
> multi-tty emacs)