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 

{
    auto lock1 = lockForShare(local_context->getCurrentQueryId(), local_context->getSettingsRef().lock_acquire_timeout);
    auto lock2 = source_table->lockForShare(local_context->getCurrentQueryId(), local_context->getSettingsRef().lock_acquire_timeout);
    auto merges_blocker = stopMergesAndWait();
    auto source_metadata_snapshot = source_table->getInMemoryMetadataPtr();
    auto my_metadata_snapshot = getInMemoryMetadataPtr();
    Stopwatch watch;
    MergeTreeData & src_data = checkStructureAndGetMergeTreeData(source_table, source_metadata_snapshot, my_metadata_snapshot);
    String partition_id = getPartitionIDFromQuery(partition, local_context);
    DataPartsVector src_parts = src_data.getDataPartsVectorInPartition(MergeTreeDataPartState::Committed, partition_id);
    MutableDataPartsVector dst_parts;
    static const String TMP_PREFIX = "tmp_replace_from_";
    for (const DataPartPtr & src_part : src_parts)
    {
        if (!canReplacePartition(src_part))
            throw Exception(
                "Cannot replace partition '" + partition_id + "' because part '" + src_part->name + "' has inconsistent granularity with table",
                ErrorCodes::BAD_ARGUMENTS);
        
        Int64 temp_index = insert_increment.get();
        MergeTreePartInfo dst_part_info(partition_id, temp_index, temp_index, src_part->info.level);
        dst_parts.emplace_back(cloneAndLoadDataPartOnSameDisk(src_part, TMP_PREFIX, dst_part_info, my_metadata_snapshot));
    }
    
    if (!replace && dst_parts.empty())
        return;
    MergeTreePartInfo drop_range;
    if (replace)
    {