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 

return false;
    }
    else
    {
        for (const auto & index : metadata_snapshot->getSecondaryIndices())
            if (index_wrapper_factory.get(index)->mayBenefitFromIndexForIn(left_in_operand))
                return true;
        for (const auto & projection : metadata_snapshot->getProjections())
        {
            if (projection.isPrimaryKeyColumnPossiblyWrappedInFunctions(left_in_operand))
                return true;
        }
        return isPrimaryOrMinMaxKeyColumnPossiblyWrappedInFunctions(left_in_operand, metadata_snapshot);
    }
}
using PartitionIdToMaxBlock = std::unordered_map<String, Int64>;
static void selectBestProjection(
    const MergeTreeDataSelectExecutor & reader,
    const StorageMetadataPtr & metadata_snapshot,
    const SelectQueryInfo & query_info,
    const Names & required_columns,
    ProjectionCandidate & candidate,
    ContextPtr query_context,
    std::shared_ptr<PartitionIdToMaxBlock> max_added_blocks,
    const Settings & settings,
    const MergeTreeData::DataPartsVector & parts,
    ProjectionCandidate *& selected_candidate,
    size_t & min_sum_marks)
{
    MergeTreeData::DataPartsVector projection_parts;