Jakub Narebski [off-list ref] writes:
What algorithm do you propose to find previous version of a line? It is
not a question with definitive answer, I think, so some heuristic would
be required. Previous version of a line might not even exists! (in that
case we would probably want to be in the place it is inserted).
Fortunately this is a situation where approximation is good enough.
I think Peff and Jonas had discussion on this in the previous thread on
tig.