Failed Storage XenMigration tasks don't clean up

I had several tries to Storage-Migrate VDIs but they failed because of lacking space on source SRs (do you really need 2 times the VDI as free space!? that's crazy stuff, guys!), I had several tasks failed.

The VMs are still alive and healthy, but on the target SR, I now have several ghosts:

They do only appear in the "attach disk dialog" from XenCenter, but these ghosts aren't shown in the SR "Storage" tab. Though I can see, they do steal several TB of space on that stoage.

IIRC you already had a bug, where XenServer didn't clean up, when stuff didn't succeed.

That should be fixed ASAP.