Hello libvirt community,

I am seeking clarification on the behavior of `virsh snapshot-delete` when used with external snapshots (created with the `--disk-only` option).

**Environment:**
- libvirt version: 10.5.0
- Kernel version: 5.14.0-503.22.1.el9_5.x86_64
- Disk image format: qcow2
- Host OS: RHEL 9.5

**Steps to reproduce:**
1. Create an external snapshot:
           virsh snapshot-create-as --domain <vm> --name snap1 --disk-only --atomic
2. Delete the snapshot:
           virsh snapshot-delete <vm> --snapshotname snap1

**Observed behavior:**
- Changes from the overlay (snapshot) file are merged into the base image.
- The snapshot metadata is removed from libvirt.
- The snapshot file remains on disk (appears orphaned).

**Questions:**
- Is the observed automatic merge of the overlay file into the base image during `snapshot-delete` the intended behavior for external snapshots in recent libvirt versions? Or we need separate `blockcommit` step.
- Should the snapshot file be deleted automatically, or is manual cleanup required?
- Is there any official documentation that clarifies this behavior for external snapshots, as most documentation seems to focus on internal snapshots?

Thank you for your help and clarification!

Best regards,  
Raj.