I am reading clickhouse mutation code. In StorageMergeTree->selectPartsToMutate() function, there is a check 
`if (current_ast_elements + commands_size >= max_ast_elements)
                break;`

I think if there are many mutations then the check result will be true, so that it will skip the remaining mutations.
But the new part's mutation is set to the last one in mutation map, and it does not apply the remaining mutations actually.
`new_part_info.mutation = current_mutations_by_version.rbegin()->first;`

Then the new part will miss the remaining mutations in future mutation job.

I think it's wrong here. Am I right?

If it is right, I will submit a PR 

{
    if (parts_mover.moves_blocker.isCancelled())
        return false;
    auto moving_tagger = checkPartsForMove(parts, space);
    if (moving_tagger->parts_to_move.empty())
        return false;
    return moveParts(moving_tagger);
}
MergeTreeData::CurrentlyMovingPartsTaggerPtr MergeTreeData::selectPartsForMove()
{
    MergeTreeMovingParts parts_to_move;
    auto can_move = [this](const DataPartPtr & part, String * reason) -> bool
    {
        if (partIsAssignedToBackgroundOperation(part))
        {
            *reason = "part already assigned to background operation.";
            return false;
        }
        if (currently_moving_parts.count(part))
        {
            *reason = "part is already moving.";
            return false;
        }
        return true;
    };
    std::lock_guard moving_lock(moving_parts_mutex);
    parts_mover.selectPartsForMove(parts_to_move, can_move, moving_lock);
    return std::make_shared<CurrentlyMovingPartsTagger>(std::move(parts_to_move), *this);
}
MergeTreeData::CurrentlyMovingPartsTaggerPtr MergeTreeData::checkPartsForMove(const DataPartsVector & parts, SpacePtr space)