BIT(1) data type value is different when using ResultSet.getShort() and PreparedStatement/Statement

A while ago we did JDBC driver upgrade from 1.4.5 to 1.6.4 and noticed an issue when using getShort-method for BIT(1) data type.

After closer inspection we wrote a test which returns the value using different methods and using PreparedStatement/Statement. Other ResultSet methods (getString, getObject, getByte, getBoolean) return the correct result (0/1), but getShort()-method produces strange results.

I am not familiar with MariaDB JDBC driver internal logic, but it seems this has to do something with text/binary protocol detection.

Driver version 1.4.5/1.5.9, using PreparedStatement:
BIT(1) field value in database 0, getShort returns 0
BIT(1) field value in database 1, getShort returns 1

Driver version 1.4.5/1.5.9, using Statement:
BIT(1) field value in database 0, getShort returns -48
BIT(1) field value in database 1, getShort returns -47

Driver version 1.6.0/1.6.4/1.6.5, using PreparedStatement:
BIT(1) field value in database 0, getShort returns -48
BIT(1) field value in database 1, getShort returns -47

Driver version 1.6.0/1.6.4/1.6.5, using Statement:
BIT(1) field value in database 0, getShort returns -48
BIT(1) field value in database 1, getShort returns -47

MariaDB server information:
version 10.1.26-MariaDB
version_comment MariaDB Server
version_compile_machine x86_64
version_compile_os Linux