Linus Torvalds [off-list ref] writes:
The original problem was:
- create new file 'x' in branch 'a'
- merge branch 'a' into branch 'b', but because of a merge conflict and
confurion in the merge, the merge result doesn't contain 'x' any more.
- try to find out what happened to 'x' after-the-fact.
Try it. Git really doesn't make it very easy, because git will notice that
'x' didn't exist before the branch either (in branch 'b'), so there will
be _no_ sign of 'x' actually going away.
That is true. The "crude attempt" patch I just sent actually catches
this, but it does not show the lossage of "new" in the "diff/diffstat"
part of the merge, when run with "git log --stat -- x". Besides, it shows
too many other uninteresting "merged two branches, resolving to lossage of
the path the same way as all the previous merges" to be really useful.