Merge branch 'ph/rebase-i-redo' into maint

"git rebase -i" moved the "current" command from "todo" to "done" a
bit too prematurely, losing a step when a "pick" did not even start.

* ph/rebase-i-redo:
  rebase -i: redo tasks that die during cherry-pick

diff --cc t/t3404-rebase-interactive.sh
Simple merge