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 

void removePartsFromWorkingSet(const DataPartsVector & remove, bool clear_without_timeout, DataPartsLock * acquired_lock = nullptr);
    void removePartsFromWorkingSet(const DataPartsVector & remove, bool clear_without_timeout, DataPartsLock & acquired_lock);
    
    
    
    DataPartsVector removePartsInRangeFromWorkingSet(const MergeTreePartInfo & drop_range, bool clear_without_timeout,
                                                     DataPartsLock & lock);
    
    
    
    void forgetPartAndMoveToDetached(const DataPartPtr & part, const String & prefix = "", bool restore_covered = false);
    
    void tryRemovePartImmediately(DataPartPtr && part);
    
    
    DataPartsVector grabOldParts(bool force = false);
    
    void rollbackDeletingParts(const DataPartsVector & parts);
    
    void removePartsFinally(const DataPartsVector & parts);
    
    void flushAllInMemoryPartsIfNeeded();
    
    
    size_t clearOldPartsFromFilesystem(bool force = false);
    void clearPartsFromFilesystem(const DataPartsVector & parts);
    
    size_t clearOldWriteAheadLogs();