Fixed in r49935.

Define "broken"?

Unless someone's putting something that doesn't belong into the message, I don't see how this would come up. Explain?

My interpretation was that the entities were shown literally. Those came from $wgLang->commaList().

Namespace names don't contain character reference entities.

$wgLang->commaList() uses comma-separator message, which hash   in most languages to combat trailing whitespace removal. Fixed in another way by Tim in r51453.