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 String partition_id = getPartitionIDFromQuery(partition, getContext());
    auto parts_to_remove = getDataPartsVectorInPartition(MergeTreeDataPartState::Committed, partition_id);
    UInt64 partition_size = 0;
    for (const auto & part : parts_to_remove)
        partition_size += part->getBytesOnDisk();
    auto table_id = getStorageID();
    getContext()->checkPartitionCanBeDropped(table_id.database_name, table_id.table_name, partition_size);
}
void MergeTreeData::checkPartCanBeDropped(const String & part_name)
{
    auto part = getPartIfExists(part_name, {MergeTreeDataPartState::Committed});
    if (!part)
        throw Exception(ErrorCodes::NO_SUCH_DATA_PART, "No part {} in committed state", part_name);
    auto table_id = getStorageID();
    getContext()->checkPartitionCanBeDropped(table_id.database_name, table_id.table_name, part->getBytesOnDisk());
}
void MergeTreeData::movePartitionToDisk(const ASTPtr & partition, const String & name, bool moving_part, ContextPtr local_context)
{
    String partition_id;
    if (moving_part)
        partition_id = partition->as<ASTLiteral &>().value.safeGet<String>();
    else
        partition_id = getPartitionIDFromQuery(partition, local_context);