mysqli savepoint rollback support missing

Am I missing something or is rollback support for savepoints missing from the mysqli extension? The commit that added savepoint support (666a83566077d1db195fd17d088062434b6202fa) is named "Add savepoint and rollback to savepoint support" yet only adds the ability to create new savepoints and release them (remove without rollback or commit). It does not add the ability to rollback to a savepoint with a "ROLLBACK TO" statement, and the "rollback" method with the savepoint name as the "name" parameter doesn't seem to accomplish this goal either.