Commits


got log: allow first-parent traversal with the commit graph


remove got_commit_graph_contains_object() Put equivalent functionality into fetch_commits_up_to() instead.


introduce got_commit_graph_fetch_commits_up_to()


introduce got_commit_graph_contains_object


do not store commits in the commit graph; saves memory


remove unused function


basic commit graph; make 'got log' use it; WIP with known bugs