My code for Support "git log --path" https://github.com/libgit2/libgit2sharp/issues/463

CommitLogExtension.cs

    public static class CommitLogExtension
    {
        public static IEnumerable<Commit> PathFilter(this IEnumerable<Commit> log, string path)
        {
            if (string.IsNullOrEmpty(path))
                return log;

            return log.Where(s =>
            {
                var pathEntry = s[path];
                var parent = s.Parents.FirstOrDefault();
                if (parent == null)
                    return pathEntry != null;

                var parentPathEntry = parent[path];
                if (pathEntry == null && parentPathEntry == null)
                    return false;
                else if (pathEntry != null && parentPathEntry != null)
                    return pathEntry.Target.Sha != parentPathEntry.Target.Sha;
                else // pathEntry!=null ^ parentPathEntry!=null
                    return true;
            });
        }
    }

Query.cs

            var ancestors = _repository.Commits
                .QueryBy(new Filter { Since = commit, SortBy = GitSortOptions.Topological | GitSortOptions.Time })
                .PathFilter(path)
                .ToList();

Maybe cant work with merged branch.

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