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 

{
    DataPartsVector total_covered_parts;
    if (!isEmpty())
    {
        auto parts_lock = acquired_parts_lock ? MergeTreeData::DataPartsLock() : data.lockParts();
        auto * owing_parts_lock = acquired_parts_lock ? acquired_parts_lock : &parts_lock;
        auto current_time = time(nullptr);
        size_t add_bytes = 0;
        size_t add_rows = 0;
        size_t add_parts = 0;
        size_t reduce_bytes = 0;
        size_t reduce_rows = 0;
        size_t reduce_parts = 0;
        for (const DataPartPtr & part : precommitted_parts)
        {
            DataPartPtr covering_part;
            DataPartsVector covered_parts = data.getActivePartsToReplace(part->info, part->name, covering_part, *owing_parts_lock);
            if (covering_part)
            {