Re: [1.8.0] Provide proper remote ref namespaces

Nicolas Pitre <nico@fluxnic.net> writes:

I agree that we do not want refs/remotes/tags/*/that-tag-people-agree-on in that case. We want to store a single copy and find it there, and that single copy has traditionally been found in refs/tags hierarchy.

I think the real issue is not necessarily that the location is shared with local tag namespace, but is the lack of a convenient way (or just BCP) to segregate what are local and what are official when transferring tags out of your repository. That is what discourages people from using tags for their personal and ephemeral use, marking some points in their own work with personal tags that are never intended to be published.

In the "interim maintainer" case without separate tag namespaces, Shawn would have been using refs/tags space to auto-follow vX.Y.Z tags that everybody agrees on and also mark his own progress with local tags, and he needs to be careful not to push out the local tags he does not want to share to his publishing repository, lest he contaminate refs/tags in repositories of other people [*1*]

But the above is less of an issue, for people who use a separate publish repository with private working repository. All they need to do is to be careful when they run "git push". By default we don't push new tags (thanks to "matching refs") nor push autopropagates tags when pushing updated branch heads out, so it suffices only to double check the tag being pushed is the right one when they run "git push $there vX.Y.Z", and to make sure they never run "git push --tags".

The problem happens when people directly start fetching or cloning from a private working-space repository, e.g. my primary integration repository has several tags that shouldn't go to k.org mixed with the vX.Y.Z tags, and that is perfectly fine as the organization gives me a uniform way to call things with names without looking at many places (i.e. refs/tags vs refs/remotes/*/tags/), yet it does not risk contaminating other people's tag namespaces because I don't allow anybody to clone nor fetch from it directly. That breaks down once people can fetch/clone from it.

Thinking aloud and not thinking things through, perhaps what's needed is a namespace private/local to the repository, i.e. instead of refs/remotes/*/tags, refs/private-tags hierarchy that I can use to store local names, and are never seen by fetch/clone?

You can swap naming around and say my (refs/tags, refs/private-tags) can be expressed with (refs/remotes/origin/tags, refs/tags), and I fully agree with that argument. The former is for tags everybody agrees on, the latter for tags that are private. The aversion I showed in my message against refs/remotes/*/tags is coming directly from this observation.

Namely, you can explain refs/remotes/origin/tags with the above line of reasoning, but how would you explain refs/remotes/$other_names/tags hierarchy? What do they mean, how they are useful, etc.

[Footnote]

*1* This issue actually is already present without "interim maintainer". I have several tags in my primary integration repository that I don't intend to publish to my repository at k.org; the gitster/git.git repository I have at GitHub is intended to disclose what I personally have, including the broken-out set of topic branches, and these tags are published there.