ayg wrote:

HTML output (indented here for better readability):

<table id="toc" class="toc" summary="Contents"><tr><td><div id="toctitle"><h2>Contents</h2></div>
<ul>

<li class="toclevel-1">
  <a href="#First_heading"><span class="tocnumber">1</span> <span class="toctext">First heading</span></a>
  <ul>
    <li class="toclevel-2">
      <a href="#subheading"><span class="tocnumber">1.1</span> <span class="toctext">subheading</span></a>
    </li>
  </ul>
</li>
<li class="toclevel-1">
  <a href="#Second_heading"><span class="tocnumber">2</span> <span class="toctext">Second heading</span></a>
</li>

</ul>
</li>
</ul>
</td></tr></table>

Note the stray </li></ul>. Probably a stack maintained incorrectly or something. Tidy fixes this on Wikimedia sites, of course.

ayg wrote:

The fault lies somewhere in Parser::formatHeadings, which gives me a headache, so don't rely on me to fix it. :) If anyone wants to find the problem, or maybe rewrite that whole little mess, feel free to attach a patch and I'll look at it.

The validator reports no problems with my test (despite admittedly ugly HTML output). Could you link to a page that the validator fails?

• [[m:User:Pathoschild/Sandbox2]]
• http://validator.w3.org/check?uri=http%3A%2F%2Fmeta.wikimedia.org%2Fwiki%2FUser%3APathoschild%2FSandbox2

ayg wrote:

As I say, Tidy will fix it if enabled, as it is on Wikimedia wikis. This is only an issue for third parties that do not use Tidy.

william.tucker wrote:

I have found the cause of this problem and have fixed it my own copy of 1.11.0.

The problem seems to be that the $prevtoclevel gets messed up right after an unindent. The solution was to add a line to set it properly after unindenting.

Add a line after the first call to tocUnindent in Parser.php. The new line should look like: $prevtoclevel = $toclevel;

So, before the change, the code looks like:

3597 if( $toclevel<$wgMaxTocLevel ) {
3598 if($prevtoclevel < $wgMaxTocLevel) {
3599 # Unindent only if the previous toc level was shown :p
3600 $toc .= $sk->tocUnindent( $prevtoclevel - $toclevel );
3601 } else {
3602 $toc .= $sk->tocLineEnd();
3603 }
3604 }

After the change, it looks like:

3597 if( $toclevel<$wgMaxTocLevel ) {
3598 if($prevtoclevel < $wgMaxTocLevel) {
3599 # Unindent only if the previous toc level was shown :p
3600 $toc .= $sk->tocUnindent( $prevtoclevel - $toclevel );
3601 $prevtoclevel = $toclevel;
3602 } else {
3603 $toc .= $sk->tocLineEnd();
3604 }
3605 }

Applied in r32387 with a parser test case. Seems good. :)

• Bug 13623 has been marked as a duplicate of this bug. ***

Went ahead and stuck this on 1.12 branch, r32998 for 1.12.1.