cryptswap overwrites existing LUKS partition

This bug is related to: https://bugs.launchpad.net/ubuntu/+source/cryptsetup/+bug/474258

In spite of the implementation of cryptswap checking for existing filesystems, I think I have encountered a bug. cryptswap still creates the swap partition if the target partition does not contain a filesystem, but a LUKS partition.

I have been able to reproduce this issue without meaning to. After adding a drive my /dev/sdX assignments shifted, and I lost a partition full of data. However, in spite of attempts to recreate the data partition, the LUKS header kept being overwritten by random data.

That's when I saw this: https://imgur.com/Zl5sYbkl.png

cryptswap has been overwriting the partitions. The partitions contained LUKS Encrypted ext4 filesystems created using gnome-disks.

I have a specific hardware device that I use for SWAP, so in a way it was my own mistake for not updating /etc/crypttab when connecting the new drive, but in my opinion cryptswap should not destroy a LUKS partition to a point where even with header it is difficult to recover any data simply because a drive has been changed. As far as I have been able to find, cryptswap with UUID is still not possible after all.