Comment 2 for bug 1778701

> How would we select which description and summary, at the least, to use from those discovered appstream files?

Good point. To be fair though, currently that isn't very clear either ;)

https://forum.snapcraft.io/t/control-which-common-id-the-adopt-info-comes-from/6091

I would imagine the easiest and most explicit way is actually adding a `common-id` attribute to the "root-level" attributes. e.g.

```
name: sampleapp-name
adopt-info: sampleapp # this is the part if I am not mistaken
common-id: org.foo.app # this is the appstreamid
apps:
  ...
parts:
  ...
```

One could argue adopt-info should actually be deprecated at that point. Assuming currently it is only communicating of which part to pick the first id in the parse-info list, which is wholly inferior to explicitly naming the desired id. The part the "master id" comes from isn't important, as the id must be unique across the entire snap anyway.

> Also, I would suggest to change this if implemented to "parse-info-appstream-all: true" or to "parse-info-all: appstream" since parse-info is pluggable and can parse other forms of metadata.

Sounds reasonable.