summaryrefslogtreecommitdiff
path: root/t/t3432-rebase-fast-forward.sh
AgeCommit message (Collapse)AuthorFilesLines
2019-08-27rebase: teach rebase --keep-baseLibravatar Denton Liu1-0/+11
A common scenario is if a user is working on a topic branch and they wish to make some changes to intermediate commits or autosquash, they would run something such as git rebase -i --onto master... master in order to preserve the merge base. This is useful when contributing a patch series to the Git mailing list, one often starts on top of the current 'master'. While developing the patches, 'master' is also developed further and it is sometimes not the best idea to keep rebasing on top of 'master', but to keep the base commit as-is. In addition to this, a user wishing to test individual commits in a topic branch without changing anything may run git rebase -x ./test.sh master... master Since rebasing onto the merge base of the branch and the upstream is such a common case, introduce the --keep-base option as a shortcut. This allows us to rewrite the above as git rebase -i --keep-base master and git rebase -x ./test.sh --keep-base master respectively. Add tests to ensure --keep-base works correctly in the normal case and fails when there are multiple merge bases, both in regular and interactive mode. Also, test to make sure conflicting options cause rebase to fail. While we're adding test cases, add a missing set_fake_editor call to 'rebase -i --onto master...side'. While we're documenting the --keep-base option, change an instance of "merge-base" to "merge base", which is the consistent spelling. Helped-by: Eric Sunshine <sunshine@sunshineco.com> Helped-by: Junio C Hamano <gitster@pobox.com> Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-27rebase: fast-forward --fork-point in more casesLibravatar Denton Liu1-10/+10
Before, when we rebased with a --fork-point invocation where the fork-point wasn't empty, we would be setting options.restrict_revision. The fast-forward logic would automatically declare that the rebase was not fast-forwardable if it was set. However, this was painting with a very broad brush. Refine the logic so that we can fast-forward in the case where the restricted revision is equal to the merge base, since we stop rebasing at the merge base anyway. Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-27rebase: fast-forward --onto in more casesLibravatar Denton Liu1-2/+2
Before, when we had the following graph, A---B---C (master) \ D (side) running 'git rebase --onto master... master side' would result in D being always rebased, no matter what. However, the desired behavior is that rebase should notice that this is fast-forwardable and do that instead. Add detection to `can_fast_forward` so that this case can be detected and a fast-forward will be performed. First of all, rewrite the function to use gotos which simplifies the logic. Next, since the options.upstream && !oidcmp(&options.upstream->object.oid, &options.onto->object.oid) conditions were removed in `cmd_rebase`, we reintroduce a substitute in `can_fast_forward`. In particular, checking the merge bases of `upstream` and `head` fixes a failing case in t3416. The abbreviated graph for t3416 is as follows: F---G topic / A---B---C---D---E master and the failing command was git rebase --onto master...topic F topic Before, Git would see that there was one merge base (C), and the merge and onto were the same so it would incorrectly return 1, indicating that we could fast-forward. This would cause the rebased graph to be 'ABCFG' when we were expecting 'ABCG'. With the additional logic, we detect that upstream and head's merge base is F. Since onto isn't F, it means we're not rebasing the full set of commits from master..topic. Since we're excluding some commits, a fast-forward cannot be performed and so we correctly return 0. Add '-f' to test cases that failed as a result of this change because they were not expecting a fast-forward so that a rebase is forced. Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-27t3432: test for --no-ff's interaction with fast-forwardLibravatar Ævar Arnfjörð Bjarmason1-29/+54
Add more stress tests for the can_fast_forward() case in rebase.c. These tests are getting rather verbose, but now we can see under --ff and --no-ff whether we skip work, or whether we're forced to run the rebase. These tests aren't supposed to endorse the status quo, just test for what we're currently doing. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-26t3432: distinguish "noop-same" v.s. "work-same" in "same head" testsLibravatar Ævar Arnfjörð Bjarmason1-31/+48
Change "same head" introduced in the preceding commit to check whether the rebase.c code lands in the can_fast_forward() case in, and thus prints out an "is up to date" and aborts early. In some of these cases we make it past that and to "rewinding head", then do a rebase, only to find out there's nothing to change so HEAD stays at the same OID. These tests presumed these two cases were the same thing. In terms of where HEAD ends up they are, but we're not only interested in rebase semantics, but also whether or not we're needlessly doing work when we could avoid it entirely. I'm adding "same" and "diff" here because I'll follow-up and add --no-ff tests, where some of those will be "diff"-erent, so add the "diff" code already. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-26t3432: test rebase fast-forward behaviorLibravatar Denton Liu1-0/+72
When rebase is run on a branch that can be fast-forwarded, this should automatically be done. Create test to ensure this behavior happens. There are some cases that currently don't pass. The first case is where a feature and master have diverged, running "git rebase master... master" causes a full rebase to happen even though a fast-forward should happen. The second case is when we are doing "git rebase --fork-point" and a fork-point commit is found. Once again, a full rebase happens even though a fast-forward should happen. Mark these cases as failure so we can fix it later. Signed-off-by: Denton Liu <liu.denton@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>