[RFC PATCH 0/1] rebase --onto detection of already applied commits

Let's consider the following operation:

  git rebase --onto new-base upstream feature

where 'feature' contains a few commits on top of 'upstream' which need to be rebased onto 'new-base'.

The problem is that some of those commits have been already applied to 'new-base' and we would like to skip them as in a regular rebase command that doesn't use '--onto', i.e. expecting to see messages like:

  warning: skipped previously applied commit [...]

However, that doesn't happen and we either get

  dropping [...] -- patch contents already upstream

or a conflict if one of the rebased commits doesn't resolve to an empty patch anymore, e.g. due to additional changes applied on the target branch.

This seems to be similar to the behavior of '--reapply-cherry-picks' and cannot be disabled via '--no-reapply-cherry-picks' or by any other means.

The proposed patch is just a quick workaround, as I'm not sure what would be the proper or recommended approach to handle the scenario described. Any advice would be highly appreciated!

Cristian Ciocaltea (1):
  rebase --onto: Skip previously applied commits

 builtin/rebase.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)