Last time I checked, decryption of incremental was working, it probably broke with recent updates, but as far as i know nobody knows the format of the increment and how to merge it to main.

After you release on PyPi , I am willing to check again

The msgstore-increment-n.db.crypt14 files are decryptable, the same as msgstore.db. However, the resulting file is not an SQLite database, but a zip file:

msgstore-increment-1.db: Zip archive data, at least v2.0 to extract, compression method=deflate

Within the zip file are numerous json files, describing changes to key WhatsApp database tables

unzip msgstore-increment-4.db
Archive:  msgstore-increment-4.db
  inflating: sequences.json          
  inflating: messages.bin            
  inflating: deletedMessages_1.json  
  inflating: jid_modified_1.json     
  inflating: media_refs_modified_1.json  
  inflating: primary_device_version_modified_1.json  
  inflating: chat_modified_1.json    
  inflating: user_device_deleted_1.json  
  inflating: user_device_modified_1.json  
  inflating: user_device_info_deleted_1.json  
  inflating: user_device_info_modified_1.json  
  inflating: receipt_user_deleted_1.json  
  inflating: receipt_user_modified_1.json  
  inflating: receipt_device_deleted_1.json  
  inflating: receipt_device_modified_1.json  
  inflating: message_add_on_receipt_device_modified_1.json  
  inflating: group_participant_device_deleted_1.json  
  inflating: group_participant_device_modified_1.json  
  inflating: frequent_deleted_1.json  
  inflating: frequent_modified_1.json  
  inflating: props_modified_1.json   
  inflating: header.json

An example being new media_refs records:

cat media_refs_modified_1.json 

{
    "media_refs": [
        {
            "path": "\/storage\/emulated\/0\/Android\/media\/com.whatsapp\/WhatsApp\/Media\/WhatsApp Images\/IMG-20240719-WA0026.jpg",
            "_id": 6124,
            "ref_count": 2
        }
    ]
}

The odd one out is the messages.bin file. This contains message table records (new messages) in protobuf format.

See:

• https://github.com/ndunks/whatsapp-protobuf
• https://github.com/sigalor/whatsapp-web-reveng

I tried to use the tools and knowledge from those repos as I'm sure that's the key to decoding the messages.bin, but I was not able to get that working.

I've tried decrypting increments using current version and everything works fine.
About the error in the issue, it shouldn't crash the program, but only report the error, so I fixed it.

For what is worth if you hit "Backup" manually in Whatsapp it seems to create just a regular msgstore.db.crypt15, which contains the very last message.

@ncatanchin Have you by any chance found a way to "unpack" messages.bin?