[PATCHv5 0/2] Fix spurious conflicts with pull --rebase

Changes since v4
  * Added a little bit of detail to the commit log about cases when
    the change can affect
  * Fixed issue pointed out by Santi with moving 12 lines of code (to
    bring definition of oldupstream variable together); the different
    pieces had important reasons for being where they were.
Changes since v1
  * Changes above, plus other commit log wording changes and lots of
    style and formatting issues for the testcase

This patch series fixes spurious conflict issues with git pull --rebase for the case where the upstream repository is *not* rebased. (There is no change in the case where the upstream repository is rebased.)

In cc85c792 (pull --rebase: be cleverer with rebased upstream branches, 2008-01-26) and d44e712 (pull: support rebased upstream + fetch + pull --rebase, 2009-07-19), the call to git-rebase was modified in an effort to reduce the number of commits being reapplied, by trying to avoid commits that upstream already had or has. It was specifically designed with an upstream that is rebased in mind. Unfortunately, it had two side effects for the non-rebased upstream case: (1) it prevented detecting if "local" patches are already upstream, and (2) it could in some cases cause more patches known to be upstream to be reapplied rather than less. This series fixes both of these issues for the non-rebased upstream case. See the commit message of the second patch for details.

It's worth noting that issue (1) above also affects the case where the upstream repository has been rebased, which this patch series does not address. As far as I can tell, fixing it would require changes (including new syntax) to format-patch to allow it to be told what 'upstream' is, and some changes to git-pull.sh/git-rebase.sh to pass it this information.

Elijah Newren (2):
  t5520-pull: Add testcases showing spurious conflicts from git pull
    --rebase
  pull --rebase: Avoid spurious conflicts and reapplying unnecessary
    patches

 git-pull.sh     |    9 ++++++++
 t/t5520-pull.sh |   62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 0 deletions(-)