revlog.py: always return tuples from parents and parentrevs There's at least one place doing parentrevs(rev) != (rev-1, -1), which is always true with revlog v0, since parentrevs returns a list in this case.

#!/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