Re: [PATCH 3/3] commit-graph: stop using full rev_info for diffs

> When we perform a diff to get the set of changed paths for a commit,
> we initialize a full "struct rev_info" with setup_revisions(). But the
> only part of it we use is the diff_options struct. Besides being overly
> complex, this also leaks memory, as we use the fake argv to
> setup_revisions() create a pending array which is never cleared.
> 
> Let's just use diff_options directly. This reduces the peak heap usage
> of "git commit-graph write --changed-paths" on linux.git from ~4GB to
> ~1.2GB.