The following (equivalent) queries return true, when the correct answer is false:

<blockquote><verbatim>
SELECT 'き' LIKE 'ね';
SELECT char(0x304d) LIKE char(0x306d);


The culprit seems to be check-in [0a99a8c4facf] on [2015-12-30 14:06:22].  Case comparison is only looking at the lower 8 bytes of unicode values.