fix(deltaBackups): update checksum after altering VHD files (#408)

Fixes vatesfr/xo-web#1606

src/remote-handlers/abstract.js

@@ -154,6 +154,13 @@ export default class RemoteHandlerAbstract {
     throw new Error('Not implemented')
   }
 
+  async refreshChecksum (path) {
+    const stream = addChecksumToReadStream(await this.createReadStream(path))
+    stream.resume() // start reading the whole file
+    const checksum = await stream.checksum
+    await this.outputFile(`${path}.checksum`, checksum)
+  }
+
   async createOutputStream (file, {
     checksum = false,
     ...options

src/vhd-merge.js

@@ -572,6 +572,7 @@ export default async function vhdMerge (
   await parentVhd.writeFooter()
 }
 
+// returns true if the child was actually modified
 export async function chainVhd (
   parentHandler, parentPath,
   childHandler, childPath
@@ -588,5 +589,7 @@ export async function chainVhd (
     childVhd.header.parentUuid = parentUuid
     childVhd.header.parentUnicodeName = parentName
     await childVhd.writeHeader()
+    return true
   }
+  return false
 }

src/xo-mixins/backups.js

@@ -295,7 +295,11 @@ export default class {
   async _chainDeltaVdiBackups ({handler, dir}) {
     const backups = await this._listVdiBackups(handler, dir)
     for (let i = 1; i < backups.length; i++) {
-      await chainVhd(handler, dir + '/' + backups[i - 1], handler, dir + '/' + backups[i])
+      const childPath = dir + '/' + backups[i]
+      const modified = await chainVhd(handler, dir + '/' + backups[i - 1], handler, childPath)
+      if (modified) {
+        await handler.refreshChecksum(childPath)
+      }
     }
   }