convert: mercurial_source: also search for copies in modified files There are some corner cases where we may have a copy in a file that isn't in the added list: - the result of a hg copy --after --force - after a merge across a (local) rename

#!/bin/sh

mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m test -d "1000000 0"
rm .hg/requires
hg tip
echo indoor-pool > .hg/requires
hg tip

true