If I use an already prepared incremental backup to merge it again with a fresh copy of the base backup it fails with the following error on 2.3:
InnoDB: Cannot create log files because data files are corrupt or not in sync with each other
And fails with following error for 2.4:
xtrabackup: error: The transaction log file is corrupted.
Steps to reproduce this issue are:
1. Take a base backup
2. Take an incremental backup
3. Copy the base backup and the incremental to another location
4. Prepare the base backup
5. Merge the incremental backup with the base backup
6. Drop the prepared base backup
7. Copy back the base backup
8. Prepare the base backup
9. Merge the already prepared incremental backup with the base backup
I attached the log file of tests with XB 2.3.
Please change the error provided with something more accurate for this situation. Also, please document incremental backups should not be used twice.