Bizarre mid-word hyperlinking issue

[Hixie]

On the [SystemChannels.platform] page, there's a link to "OptionalMessageChannel", at least there should be, but somehow it's becoming a link to "MessageChannel", with only half the word hyperlinked???

https://master-docs-flutter-io.firebaseapp.com/flutter/services/SystemChannels/platform-constant.html

[jcollins-g]

I just ran into this by accident yesterday in my branch and have a patch coming with #1524. This sort of thing happens with any constant due to a bug in how they're rendered. It does some blind string substitution without paying attention to word boundaries, and misses escapes on types ala #1529.

[jcollins-g]

Also, the generated string (with hyperlinks!) is occasionally truncated on the enclosing element's page, creating ugly and invalid HTML.