Fix copy detection corner case We were aborting if the copied from rev was before the cut-off limit, rather than the copied _to_ rev. The copied from rev can be arbitrarily old.

#!/bin/sh

hg init
python -c 'print "confuse str.splitlines\nembedded\rnewline"' > a
hg ci -Ama -d '1 0'
echo clean diff >> a
hg ci -mb -d '2 0'
hg diff -r0 -r1