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 

if (!added_columns.contains(col) || deleted_columns.contains(col))
                    throw Exception("Existing column " + backQuoteIfNeed(col) + " is used in the expression that was "
                        "added to the sorting key. You can add expressions that use only the newly added columns",
                        ErrorCodes::BAD_ARGUMENTS);
                if (new_metadata.columns.getDefaults().count(col))
                    throw Exception("Newly added column " + backQuoteIfNeed(col) + " has a default expression, so adding "
                        "expressions that use it to the sorting key is forbidden",
                        ErrorCodes::BAD_ARGUMENTS);
            }
        }
    }
    if (!new_metadata.secondary_indices.empty())
    {
        std::unordered_set<String> indices_names;
        for (const auto & index : new_metadata.secondary_indices)
        {
            MergeTreeIndexFactory::instance().validate(index, attach);
            if (indices_names.find(index.name) != indices_names.end())
                throw Exception(
                        "Index with name " + backQuote(index.name) + " already exists",
                        ErrorCodes::LOGICAL_ERROR);
            indices_names.insert(index.name);
        }
    }
    if (!new_metadata.projections.empty())
    {
        std::unordered_set<String> projections_names;
        for (const auto & projection : new_metadata.projections)
        {
            if (projections_names.find(projection.name) != projections_names.end())