Re: xml.el produces incorrect sexp for empty element.

[mah@everybody.org (Mark A. Hershberger)]

Thien-Thi Nguyen <ttn@glug.org> writes:

> mah@everybody.org (Mark A. Hershberger) writes:
>
>    * xml.el (xml-parse-tag): Fixed incorrect handling of empty elements.
>
> because i'm not an xml expert i don't understand what was incorrect
> before.  could you reword this in the sense of:
>
>   * xml.el (xml-parse-tag): Handle empty elements [IN CORRECT WAY].
>
> w/ a touch more detail on the correction made?

I did this with my previous patches, but since I made a mistake in
that last patch, thank you for the opportunity to fix my mistake.

    The old xml-parse-region parses the following two bits of XML into
    different sexps.

        "<xml/>" is parsed to ((xml nil ("")))

    while

        "<xml></xml>" is parsed to ((xml nil))

    <URL: http://www.w3.org/TR/2000/REC-xml-20001006#sec-starttags>
    states that "An element with no content is said to be empty.] The
    representation of an empty element is either a start-tag
    immediately followed by an end-tag, or an empty-element tag."

    So, "<xml/>" is equivilent to "<xml></xml>", but they don't parse
    the same in xml.el.
    
The following patch and changelog fix the problem.

mah@everybody.org (Mark A. Hershberger) writes:                         
                                                                         
   * xml.el (xml-parse-tag): Fixed handling of empty elements so that
     "<x/>" parses the same as "<x></x>".

*** xml.el.~1.18.~	Thu Mar 20 12:01:04 2003
--- xml.el	Fri May 30 15:37:12 2003
***************
*** 221,228 ****
        ;; is this an empty element ?
        (if (looking-at "/[ \t\n\r]*>")
  	  (progn
! 	    (forward-char 2)
! 	    (nreverse (cons '("") children)))
  
  	;; is this a valid start tag ?
  	(if (eq (char-after) ?>)
--- 221,228 ----
        ;; is this an empty element ?
        (if (looking-at "/[ \t\n\r]*>")
  	  (progn
! 	    (goto-char (match-end 0))
! 	    (nreverse children))
  
  	;; is this a valid start tag ?
  	(if (eq (char-after) ?>)



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