The current zipFile implementation supports the allowZip64,which can make large zip files.
There is a bug in the current implementation of close method ,where the extra field is overwritten .

To reproduce it :
1.Create a directory with more then 4 GB of data(spread over many files).
2.Make the zip of those files using the any rar achiever which adds NTFS metadata(mtime,atime and ctime) of files in the zip.
3.Apped a new file to the zip using the zip library .

When i open the zip again ,the files processed after the ZIP64_LIMIT is reached will have there extra fields overwritten.

I have attached the zip which contained the python used to add the new file, and the images of zip archive before adding new files and after.