Support multiple anonymous sessions

[nicola-cab]

What, How & Why?

Allow multiple anonymous sessions.
Fixes: #4607

[nirinchev]

This would be a breaking change and not what #4607 is asking for. What I'm suggesting there is that we add a parameter to the anonymous credentials that would indicate whether to reuse or not reuse existing anonymous users. The default value should be true to make sure that existing applications that authenticate anonymous users continue behaving the same way. If the user opts out of reusing an existing user, then we should authenticate a new user and return that.

[nicola-cab]

This would be a breaking change and not what #4607 is asking for. What I'm suggesting there is that we add a parameter to the anonymous credentials that would indicate whether to reuse or not reuse existing anonymous users. The default value should be true to make sure that existing applications that authenticate anonymous users continue behaving the same way. If the user opts out of reusing an existing user, then we should authenticate a new user and return that.

OK, my change was too extreme, I redesign the code as per your suggestion.

[tgoyne]

operator= and the copy constructor also need to copy m_reuse_anonymous_credentials.

It might also make sense to instead have reused and unique anonymous users instead be different values in the credentials provider enum rather than having a bool field which is only applicable to one of the credential types.

[nirinchev]

Looks fine to me, though it'd be a good idea to add some tests to verify that it works as intended.

[nicola-cab]

Looks fine to me, though it'd be a good idea to add some tests to verify that it works as intended.

Done, please approve, and I will merge the PR once CI has run successfully.

[nirinchev]

It seems fine to me, but I strongly suggest you get a review from someone on the Core team.

[nicola-cab]

@jedelbo @tgoyne can you please have a look as well?

[tgoyne]

TestSyncManager takes care of this.

[nicola-cab]

OK, let me remove the line.