fix(backups/_VmBackup#_selectBaseVm): cant read .uuid of undefined srcVdi (#6034)

See xoa-support#4263

The debug message is now clearer and has correct associated data.

@xen-orchestra/backups/_VmBackup.js

@@ -333,13 +333,16 @@ exports.VmBackup = class VmBackup {
 
     const baseUuidToSrcVdi = new Map()
     await asyncMap(await baseVm.$getDisks(), async baseRef => {
-      const snapshotOf = await xapi.getField('VDI', baseRef, 'snapshot_of')
+      const [baseUuid, snapshotOf] = await Promise.all([
+        xapi.getField('VDI', baseRef, 'uuid'),
+        xapi.getField('VDI', baseRef, 'snapshot_of'),
+      ])
       const srcVdi = srcVdis[snapshotOf]
       if (srcVdi !== undefined) {
-        baseUuidToSrcVdi.set(await xapi.getField('VDI', baseRef, 'uuid'), srcVdi)
+        baseUuidToSrcVdi.set(baseUuid, srcVdi)
       } else {
-        debug('no base VDI found', {
-          vdi: srcVdi.uuid,
+        debug('ignore snapshot VDI because no longer present on VM', {
+          vdi: baseUuid,
         })
       }
     })

CHANGELOG.unreleased.md

@@ -16,6 +16,7 @@
 - [Tables/actions] Fix collapsed actions being clickable despite being disabled (PR [#6023](https://github.com/vatesfr/xen-orchestra/pull/6023))
 - [Backups] Fix: `Error: Chaining alias is forbidden xo-vm-backups/..alias.vhd to xo-vm-backups/....alias.vhd` when backuping a file to s3 [Forum #5226](https://xcp-ng.org/forum/topic/5256/s3-backup-try-it)
 - [Delta Backup Restoration] `VDI_IO_ERROR(Device I/O errors)` [Forum #5727](https://xcp-ng.org/forum/topic/5257/problems-building-from-source/4) (PR [#6031](https://github.com/vatesfr/xen-orchestra/pull/6031))
+- [Delta Backup] Fix `Cannot read property 'uuid' of undefined` when a VDI has been removed from a backed up VM (PR [#6034](https://github.com/vatesfr/xen-orchestra/pull/6034))
 
 ### Packages to release