[wp-trac] [WordPress Trac] #14857: Shortcode causes preceding HTML tag to disappear

[WordPress Trac]

#14857: Shortcode causes preceding HTML tag to disappear
--------------------------+-------------------------------------------------
 Reporter:  cymric        |       Owner:                 
     Type:  defect (bug)  |      Status:  new            
 Priority:  normal        |   Milestone:  Awaiting Review
Component:  Shortcodes    |     Version:  3.0.1          
 Severity:  normal        |    Keywords:                 
--------------------------+-------------------------------------------------
 On my Wordpress 3.0.1 installation (Atahualpa theme 3.4.4, PHP 5.2.12 +
 Zend 2.2.0 running on SunOS 5.10) I've succesfully added a shortcode which
 allows me to 'write' an image into the text of a contribution; all the
 hard work of figuring out where it should be displayed, how wide the
 container should be, and what the caption looks like is handled by the
 shortcode callback function. It works very well, but for one weird issue.

 If I use a HTML construct like

 {{{
 <p>[photo location="..." link="..."]Lorem ipsum dolor sit amet...
 }}}

 where [photo...] expands into a complex <span>, then on random occasions
 the shortcode processing will swallow the preceding <p> tag. If I didn't
 have specific CSS applied to distinguish between the appearance of various
 <a> tags in <p> text (which rely on very specific child selectors, amongst
 which the presence of an opening <p> tag) I would never have seen the
 problem. If I modify the HTML to

 {{{
 <p><!---->[photo location="..." link="..."]Lorem ipsum dolor sit amet...
 }}}

 which introduces a non-visible break between the <p> tag and the
 shortcode, then the <p> tag is left alone. Oddly enough, the comment is
 not removed either.

 Unfortunately there seems to be no pattern to this 'gobbling up' of
 preceding tags; I only know it is there, and how to work around it. On a
 previous occasion (dealing with ticket #14468) I had been instructed to up
 the PCRE backtrack limit, but setting this at an in my opinion ridiculous
 value of 5000000 did not cause the problem to disappear. I can provide a
 visual demonstration of the problem if required.

-- 
Ticket URL: <http://core.trac.wordpress.org/ticket/14857>
WordPress Trac <http://core.trac.wordpress.org/>
WordPress blogging software