Analysis:
========

Full text search on InnoDB tables using binary collation
for indexed columns does not return case sensitive matches.

For case sensitive matches, it is recommended to use binary
collation for the indexed columns. During the processing
of the FTS query, the query string is always converted to
lower case regardless of the collation type. Hence, case
insensitive matches were returned during the FTS search.

Fix:
===
Don't convert the query string to lower case during FTS
search if the collation of the indexed column is of
binary type.