Output fallthrough

[pdawyndt]

Here are some cases where output from one testcase falls through to the next testcase. All seem to have the b’ pattern in the output.

• https://dodona.be/nl/submissions/16169491/#code
• https://dodona.be/nl/submissions/16174540/#code
• https://dodona.be/nl/submissions/16178351/#code
• https://dodona.be/nl/submissions/16080236/#code