Merge branch 'js/status-pre-rebase-i'

Merge branch 'js/status-pre-rebase-i'

After starting "git rebase -i", which first opens the user's editor
to edit the series of patches to apply, but before saving the
contents of that file, "git status" failed to show the current
state (i.e. you are in an interactive rebase session, but you have
applied no steps yet) correctly.

* js/status-pre-rebase-i:
  status: be prepared for not-yet-started interactive rebase