> Huh. Sorry, I didn't notice the change to the value being switch'ed
> on. Why change this? This is a pretty dangerous (IMHO) deviation from
> MySQL which may cause problems, and is unnecessary. Why not just stick
> with exactly what MySQL is doing in 5.6, plus whatever minor changes
> are needed to support MariaDB-format microsecond time?

Because changes to support MariaDB format make switch into a dead code.
Or into redundant code, depending on whether I put if() before the
switch or after. Because this if() has to be there, and it does cover
all temporal type variants, MariaDB or MySQL.

I rather add a test case to verify that 5.6-style temporal2 types are
mapped correctly.