local-clone: extract the listing of caches to copy Right now, the clone only copies the branchmap caches. There are multiple other valuable caches that we should copy and extensions might add their own. So we add a function to list the cache files to copy from the repository. The repository argument is unused but extensions will want it.

local-clone: extract the closure copying caches Closures often get on the way. They are not much value in having that as a closure so I'm extracting it at the module level.

test: add isolated prune case (to test-obsolete-bundle-strip.t) This adds a test where the prune marker is not related to any other obsmarkers.

test-obsolete-bundle-strip: add a complex split and fold case This is a more complex case that checks the logic used when split and fold gets into play.

test-obsolete-bundle-strip: add cases with prune on missing revs Same as the previously added case, but the prune is no longer known locally. This will mostly matter for the strip testing. Introducing the test early will help clarify patches related to strip.

obsolete: fix relevant-obsmarkers computation on pruned changeset The markers pruning a node was not directly considered relevant for the pruned node, only to its parents. This went unnoticed during obsmarkers exchange because all ancestors of the pruned node would be included in the computation. This still affects obsmarkers exchange a bit since "inline" prune markers would be ignored (see second test case). This went unnoticed, because in such case, we always push another obsolescence markers for that node. We add explicit tests covering this case. (The set of relevant changeset is use in the obsmarkers discovery protocol used in the evolve experimental extension, the impact will be handled on the extension side).

test: add a test file for relevant obsmarkers and its usage The logic around obsmarkers "relevant" to a set of revs have a couple of test around in other places but no systematic testing. In addition, all the current testing focus on the exchange case (we looks at relevant markers for '::heads'). For bundles, we'll need something a bit different. We'll no longer have set of revision going down to the repository roots. So we'll have to test these cases too. In addition, stripping obsmarkers will introduce new logic around obsmarkers that will need testing too. So a new test file make sense here. We start with a simple tests, more advanced cases are coming in the next changesets. The extra testing catch a minor bug (later in the series).