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Addendum: note how those code sequences have been very carefully constructed to be as innocuous as possible. No XORs, simple Fletcher32 style checksum, no memory references that would show up as xrefs in IDA. You'll only find them if you actually carefully reverse the code.
The checksum is computed (check_evil()) right in the middle of theme loading (before another loop, so it doesn't stand out), and result is checked in the middle of the font code. So there's no way to find them other than just reading, reading, reading code.
