Each `Update.download()` overwrote `this.downloadedBytes` without closing the
previous resource, so the whole previous update payload stayed in the webview
resources table. The previous resource is now closed once the new download
succeeded (so a failed retry still leaves the earlier download installable).
Not covered by e2e: the fixture manifest has no valid signature, so a
download can never succeed there.
plugins/updater/guest-js/index.ts
Lucas Fernandes Nogueira
7b7c7c6251