MySQL migration error with default JSON data

[Floppy]

::Error: BLOB, TEXT, GEOMETRY or JSON column 'pagination_settings' can't have a default value (Mysql2::Error)

See original report in #3138.

[Floppy]

@NeoMod can I ask which version of MySQL/MariaDB you're running, please?

[Floppy]

This seems to be because MySQL 8+ wants the default as an expression, not a literal. But surely Rails should be handling that for us? See https://dev.mysql.com/doc/refman/8.0/en/data-type-defaults.html

[Floppy]

Worst case is we don't set a default for MySQL. The code will use default values from elsewhere anyway, so it probably won't matter at all.

[Floppy]

This works OK with MariaDB 10, just tested it...