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 

const StorageMetadataPtr & metadata_snapshot, String * , TableLockHolder & ,
    std::unique_lock<std::mutex> & currently_processing_in_background_mutex_lock,
    bool & were_some_mutations_for_some_parts_skipped)
{
    size_t max_ast_elements = getContext()->getSettingsRef().max_expanded_ast_elements;
    auto future_part = std::make_shared<FutureMergedMutatedPart>();
    if (storage_settings.get()->assign_part_uuids)
        future_part->uuid = UUIDHelpers::generateV4();
    CurrentlyMergingPartsTaggerPtr tagger;
    if (current_mutations_by_version.empty())
        return {};
    size_t max_source_part_size = merger_mutator.getMaxSourcePartSizeForMutation();
    if (max_source_part_size == 0)
    {
        LOG_DEBUG(
            log,
            "Not enough idle threads to apply mutations at the moment. See settings 'number_of_free_entries_in_pool_to_execute_mutation' "
            "and 'background_pool_size'");
        return {};
    }
    auto mutations_end_it = current_mutations_by_version.end();
    for (const auto & part : getDataPartsVector())
    {
        if (currently_merging_mutating_parts.count(part))
            continue;
        auto mutations_begin_it = current_mutations_by_version.upper_bound(getUpdatedDataVersion(part, currently_processing_in_background_mutex_lock));
        if (mutations_begin_it == mutations_end_it)
            continue;