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
hg init
touch a
hg add a
hg ci -m "a" -d "1000000 0"
echo 123 > b
hg add b
hg diff --nodates
hg diff --nodates -r tip
echo foo > a
hg diff --nodates
hg diff -r ""
hg diff -r tip -r ""
true