hGetSomeString reads one byte at a time, so unicode bytes are not composed.
The problem comes when outputting that to the console with hPut; that
tried to apply the handle's encoding, and so we get mojibake.
Instead, use ByteStrings, and only convert it to a string for parsing, not
for display.
Note that there are a couple of other things that use hGetSomeString,
which I've left as-is for now.
