add 3.1.2

add 3.1.2
Revert "add 3.1.2"

This reverts commit 8725e2970dc12a7182ff21b9e2dc18043e10ed99.
Revert "Revert "add 3.1.2""

This reverts commit 5a14e2bcaaf19ea34b5eeec12e6a43c27ca91de8.