rebase: ensure rebase does not revive extinct revision Here, we exclude hidden changesets from a rebase operation. If we don't, a rewritten version of the hidden changesets will be created by rebase. Those rewritten versions won't be hidden and will likely conflict with other rewriting or revive pruned changeset. Moreover, rewriting hidden revisions will surprise the user. This change would not be necessary if changelog filtering were already in core. But it's fairly cheap and helps to increase the test-suite for such filtering. Once changelog level filtering is added, hidden changes will be automatically excluded or included according to the global --hidden flags. Plain ignoring them is good enough for now.