Merge branch 'jk/rev-list-verify-objects-fix'

"git rev-list --verify-objects" ought to inspect the contents of objects and notice corrupted ones, but it didn't when the commit graph is in use, which has been corrected. * jk/rev-list-verify-objects-fix: rev-list: disable commit graph with --verify-objects lookup_commit_in_graph(): use prepare_commit_graph() to check for graph