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 a
cd a
hg init
echo 123 > a
hg add a
hg commit -m "a" -u a -d "1000000 0"

cd ..
mkdir b
cd b
hg init
echo 321 > b
hg add b
hg commit -m "b" -u b -d "1000000 0"

hg pull ../a
hg pull -f ../a
hg heads