- a NUL or '$' could get replaced with another NUL or '$' - Replacement characters didn't get their first bit set to 0 (`&^ 128`) - The test case used the index number instead of the value of the rune.
- a NUL or '$' could get replaced with another NUL or '$' - Replacement characters didn't get their first bit set to 0 (`&^ 128`) - The test case used the index number instead of the value of the rune.