Commit bbe6dbec81d2050fb52b600bc27e2dacdc780e77

Russell Belfer 2012-11-14T23:29:48

Add explicit git_index ptr to diff and checkout A number of diff APIs and the `git_checkout_index` API take a `git_repository` object an operate on the index. This updates them to take a `git_index` pointer explicitly and only fall back on the `git_repository` index if the index input is NULL. This makes it easier to operate on a temporary index.