Before commit 5d317c2, this encoding happens in the parser before
calling the ParserAfterTidy hook, at this stage, the input usually
don't contain any raw-text elements, all good;
After commit 5d317c2 but before the core is actively using the
RemexCompatFormatter for OutputTransform, the bug can only be triggered
by extensions. But for now, the transform can happen on every page
with a ToC.
The issue and the fix is similar to T255007 and commit c44a395, which
5d317c2 follows-up to, so I am a bit confused why this stays broken.
Bug: T406391
Change-Id: I41959bf5ee243bdcfba571eb8f121fb571d960db
(cherry picked from commit e928409b4f7a81a8ee02d563c18829d5524e0fa6)
fc5f2119b0