Wikimedia Bugzilla is closed!

Reedy brought to our attention HtmlFormatter.php is generating lots of PHP warnings fron line 190. Looking at the logs, there are lots of things like:

Oct  3 00:13:09 10.0.8.22 apache2[25132]: PHP Warning:  DOMDocument::createElement() [<a href='domdocument.createelement'>domdocument.createelement</a>]: unterminated entity reference {}= \int_a^b f(x) \, dx - \int_c^b f(x) \, dx \\#012 &amp;{} = \int_a^b f(x) \, dx + \int_b^c f(x) \, dx#012\end{align}] in /usr/local/apache/common-local/php-1.20wmf12/extensions/MobileFrontend/includes/HtmlFormatter.php on line 190

and

Oct  3 00:14:28 10.0.11.55 apache2[9646]: PHP Warning:  DOMDocument::createElement() [<a href='domdocument.createelement'>domdocument.createelement</a>]: unterminated entity reference W Magnum hunting load with 500 gr. SP bullet by Hornady.] in /usr/local/apache/common-local/php-1.20wmf12/extensions/MobileFrontend/includes/HtmlFormatter.php on line 190

It seems likely related to the changes introduced in https://gerrit.wikimedia.org/r/#/c/23648/3

We traced the later warning to the following image:
http://commons.wikimedia.org/wiki/File:500SWHornady01.png
Which appears on:
https://en.wikipedia.org/wiki/.500_S%26W_Magnum

Perhaps exporting the article and doing some local testing with MobileFrontend beta with images disabled might help unearth the cause.