del transaction before lock before wlock This way rollbacks happen while the repo is still locked. Deleting lock before wlock is not strictly necessary, but is more consistent with the locking order.

#!/bin/sh

mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m "test" -d "1000000 0"
hg verify
hg parents
hg status
hg rollback
hg verify
hg parents
hg status