Ampersand in unreified tag is causing problems when indirected through a function

(Bug, Closed -> Fixed, Priority: Critical, Test Status: No automated tests yet , Reported By Bad Link: Thing 3y284oe not found, )

Tag Sets, Functions

Summary: This is currently repro'ed in New MySQL Space with the "Branch & Claw" Tag, which fails to display its Page Header, while "Core Game" succeeds.

The issue has to do with the fact that Page Header is calling out to My Page Header._apply. We're getting a crash in the XML parser again, which means that something is getting through unescaped.