On https://en.wikipedia.org/wiki/Special:BookSources/0312898959, something is going wrong somewhere between SpecialBookSources, OutputPage, Parser, Tidy or Linker::thumbnail.
It contains the following HTML:
```lang=html
<div class="hatnote">For assistance, see <a href="/wiki/Help:ISBN" title="Help:ISBN">Help:ISBN</a>.</div>
<div class="thumb tleft"><div class="thumbinner" style="width:402px;">
<div class="noresize">
<map name="ImageMap_1_1744687168"><area href="#South_America" shape="poly" coords="90,79,70,91,96,160,115,162,135,100" alt="South America" title="South America"/><area href="#Africa" shape="poly" coords="176,49,159,53,141,68,156,95,187,143,222,143,230,83,200,56" alt="Africa" title="Africa"/><area href="#Europe" shape="poly" coords="179,4,153,36,158,49,201,55,208,42,203,14" alt="Europe" title="Europe"/><area href="#Europe" shape="poly" coords="203,14,239,3,333,15,307,36,285,32,263,34,251,34,225,33,208,35" alt="Russia" title="Russia"/><area href="#Asia" shape="poly" coords="207,34,198,55,222,77,254,88,284,104,306,108,314,94,333,18,301,34" alt="Asia" title="Asia"/><area href="#Australasia" shape="poly" coords="314,91,307,105,282,120,284,139,328,156,355,140,366,115" alt="Australasia" title="Australasia"/><area href="#United_States" shape="poly" coords="58,15,39,11,11,31,47,25" alt="United States" title="United States"/><area href="#United_States" shape="poly" coords="49,38,78,38,92,43,99,42,102,40,103,40,104,43,87,66,65,65,57,59,45,58,40,49" alt="United States" title="United States"/><area href="#Canada" shape="poly" coords="58,15,46,26,48,37,79,37,93,43,102,40,105,45,121,40,120,18,122,6,130,3,124,1" alt="Canada" title="Canada"/><area href="#Central_America" shape="poly" coords="45,57,57,58,65,66,75,71,74,74,67,79,47,70" alt="Central America" title="Central America"/><area href="#Greenland" shape="poly" coords="132,2,122,6,127,23,134,25,154,15,164,3" alt="Greenland" title="Greenland"/></map>
<img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c3/BlankMap-World.png/400px-BlankMap-World.png" width="400" height="197" class="thumbimage" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c3/BlankMap-World.png/600px-BlankMap-World.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c3/BlankMap-World.png/800px-BlankMap-World.png 2x" data-file-width="1500" data-file-height="740" usemap="#ImageMap_1_1744687168"/>
</div>
<div class="thumbcaption"><div class="magnify"><a href="/wiki/File:BlankMap-World.png" class="internal" title="Enlarge"/></div>Select your region from the map above</div>
</div></div>
<div class="toc" style="float:right">
<div class="toctitle"><b>Brief Table of Contents</b></div>
<ol><li> <a href="#Notes">Notes</a></li>
<li> <a href="#Online_text">Online text</a></li>
<li> <a href="#Online_databases">Online databases</a></
```
The `<a>` for the Enlarge link in the `div.magnify` element is rendered as if it were a void element. Since anchor tags are not legal void elements, when parsed in Chrome, it stays open.
This is causing:
* The entire caption to become part of the link.
* The next heading to become part of the link
* The whitespace before first item in the table of contents to become a link.
* Because of the extra link, the first TOC item is now 1em offset to the right (see screenshot)
The same wikitext is also rendered on [Wikipedia:Book_sources](https://en.wikipedia.org/wiki/Wikipedia:Book_sources), however there it renders fine with an open and close tag:
```lang=html
<div class="magnify"><a href="/wiki/File:BlankMap-World.png" class="internal" title="Enlarge"></a></div>
```
Screenshot of the breakage on Special:BookSources:
{F175974}
Screenshot of Wikipedia:Book_sources by comparison, which is unaffected (possibly thanks to Tidy or some other post-processing).
{F175976}
Screenshot of live DOM, showing the unclosed `<a>` gets re-created in every block level element until it finds a way to close it. Which is causing whitespace that would otherwise be insignificant, to become significant and render, thus pushing away other content (like the first list item).
{F175978}
The relevant code in Linker::makeThumbLink2:
```lang=php
$zoomIcon = Html::rawElement( 'div', array( 'class' => 'magnify' ),
Html::rawElement( 'a', array(
'href' => $url,
'class' => 'internal',
'title' => wfMessage( 'thumbnail-more' )->text() ),
"" ) );
}
}
$s .= ' <div class="thumbcaption">' . $zoomIcon . $fp['caption'] . "</div></div></div>";
```
I tried many different ways, but `Html::rawElement( 'a', array(), "" );` always produces `<a></a>`. Having said that, SpecialBookSources does to weird magic by including the raw wikitext directly into the page to be rendered, thus bypassing some processes. What's causing this?