If I do
git difftool -y --find-renames master
I get diffs of any file with the original version on the branch, so if I've renamed 'a' to 'b' and changed it, I get the differences between the current 'b' and the original 'a'. But if, instead, I do
git difftool -y --find-renames master b
it gets compared with /dev/null. This is quite confusing.
Is there any way to get git diff to do what I expect?