fix: Subscribe API Meta and UserMeta fields wrong

[fovecifer]

Description

I am using Subscribe API to listening the key changes, I found the Meta and UserMeta in pb.KV were wrong

[mangalaman93]

Thank you for the PR. I do not think this is a bug. This is expected because the internal meta is not useful to the caller and hence, we write the UserMeta into meta before publishing.

[fovecifer]

Thank you for the PR. I do not think this is a bug. This is expected because the internal meta is not useful to the caller and hence, we write the UserMeta into meta before publishing.

Why not write the UserMeta into UserMeta? as a caller of the Subscribe API, I was confused where to get my UserMeta

[mangalaman93]

Yes, that maybe right but I would not like to break the API. Is it a big deal for your use case?

[fovecifer]

Yes, that maybe right but I would not like to break the API. Is it a big deal for your use case?

Yes, I use this subscribe API to implement "replication" feature. I need the UserMeta and the "bitDiscardEarlierVersions" of Meta.
Currently, I use my fork of badger in my project, it is doing well.

[mangalaman93]

Do you mind explaining why you are using a fork? Is this PR the reason for it? Thank you patiently answering my questions.