Remove field length to maximize future compatible.

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.0' into 2.1
Merge branch '2.1' into 2.2

Signed-off-by: crynobone <crynobone@gmail.com>
Release v2.1.6

Signed-off-by: crynobone <crynobone@gmail.com>
Merge branch '2.1' into 2.2
Merge branch '2.2'