unit testing - Example invalid utf8 string?

Question

I'm testing how some of my code handles bad data, and I need a few series of bytes that are invalid UTF-8.

Can you post some, and ideally, an explanation of why they are bad/where you got them?

Answer 1

Take a look at Markus Kuhn's UTF-8 decoder capability and stress test file

You'll find examples of many UTF-8 irregularities, including lonely start bytes, continuation bytes missing, overlong sequences, etc.