view tests/test-rollback @ 2703:d32b31e88391

run-tests.py: fix diff output when test-foo.out doesn't exist.

Previously, if test-foo.out doesn't exist and test-foo outputs
something, the first line of the diff will look like this:

-+changeset:   0:0acdaf898367

(note the leading "-")

#!/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