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 

addPartContributionToColumnAndSecondaryIndexSizes(part);
        addPartContributionToDataVolume(part);
    }
    auto part_in_memory = asInMemoryPart(part);
    if (part_in_memory && getSettings()->in_memory_parts_enable_wal)
    {
        auto wal = getWriteAheadLog();
        wal->addPart(part_in_memory);
    }
    if (out_covered_parts)
    {
        for (DataPartPtr & covered_part : covered_parts)
            out_covered_parts->emplace_back(std::move(covered_part));
    }
    return true;
}
MergeTreeData::DataPartsVector MergeTreeData::renameTempPartAndReplace(
    MutableDataPartPtr & part, SimpleIncrement * increment, Transaction * out_transaction, MergeTreeDeduplicationLog * deduplication_log)
{
    if (out_transaction && &out_transaction->data != this)
        throw Exception("MergeTreeData::Transaction for one table cannot be used with another. It is a bug.",
            ErrorCodes::LOGICAL_ERROR);
    DataPartsVector covered_parts;
    {
        auto lock = lockParts();
        renameTempPartAndReplace(part, increment, out_transaction, lock, &covered_parts, deduplication_log);
    }
    return covered_parts;
}
void MergeTreeData::removePartsFromWorkingSet(const MergeTreeData::DataPartsVector & remove, bool clear_without_timeout, DataPartsLock & )