MultiNamespacedCacheBuilder duplicates objects if provided empty string "" along with namespaces

[gcs278]

We stumbled upon this as we were working through issues in our code base. If you include an empty string "" along with other namespaces, MultiNamespacedCacheBuilder will duplicate those object in the cache:

cache.MultiNamespacedCacheBuilder([]string{
	"namespace1"
	"",
}),

It appears "" lists all objects, but this results in objects in "namespace1" being duplicated in the cache.

Now, I understand from some issues like https://github.com/kubernetes-sigs/controller-runtime/issues/1006, MultiNamespacedCacheBuilder is not intended to list all namespaces, which is what the "" is appearing to do.

This was a mistake on our part, as previously we thought emtpy quote gave cluster scoped resources, but it is now understood that cluster scoped resources are automatically included with MultiNamespacedCacheBuilder. We have resolved our issue.

So creating this issue to describe the weird results we saw, to see if the developers here thought it was anything worth fixing, or if it was expected.

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/lifecycle rotten

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/close

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@k8s-triage-robot: Closing this issue.

In response to this:

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues and PRs.

This bot triages issues and PRs according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
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/close

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