Hi Joel On 22/07/2020 18:09, Joel Marshall wrote: > I've attached a couple of screenshots from tortoisegit. The branches > are too long to show in their entirety, but this should give you an > idea of what I'm talking about. The highlighted commit is the head of > the branch that I'm rebasing onto. Interestingly, I just noticed that > while --rebase merges reports that it's rebasing 202 commits > intitially, upon manually reconciling the first conflict it reports > that it is rebasing 183 commits. Thanks, the rebased topologies are certainly quite different, what is the topology before the rebase? Looking at the --rebase-merges result it looks like the second parents of merges that are being rebased have ancestors in the upstream branch. If that is the case then I think it is working as intended. Are you able to run git log --format=%ad --graph $upstream..HEAD before and after the rebase to check that? Best Wishes Phillip > On Wed, Jul 22, 2020 at 10:22 AM Phillip Wood <phillip.wood123@xxxxxxxxx> wrote: >> >> Hi Joel >> >> On 21/07/2020 22:20, Joel Marshall wrote: >>> Thank you for filling out a Git bug report! >>> Please answer the following questions to help us understand your issue. >>> >>> What did you do before the bug happened? (Steps to reproduce your issue) >>> This is a difficult one to give proper steps to reproduce. The issue >>> is with rebase's --rebase-merges flag. We recently switched from using >>> rebase with the --preserve-merges option to --rebase-merges. Most of >>> the time the output is the same, but sometimes it is very different. >>> I'm unable to determine whether this is by design or a bug. >> >> --preserve-merges is buggy if you rearrange the commits (this is way >> --rebase-merges was added), if you're just rebasing without reordering >> anything then I think the result should be the same though there may be >> some corner cases I'm not aware of. Are you able to share the topology >> before rebasing and after with --preserve-merges and --rebase-merges? >> >>> What did you expect to happen? (Expected behavior) >>> Resulting graph after running rebase --rebase-merges is the same as >>> running rebase --preserve-merges. >>> >>> What happened instead? (Actual behavior) >>> Using --rebase merges tries to pick substantially more commits and >>> results in merge commits with no parent commit when viewing log in >>> reverse chronological order. >>> >>> What's different between what you expected and what actually happened? >>> When the issue does occur (it doesn't for all rebases) it results in >>> two completely different logs and picks commits that are apparently >>> not part of the branch being rebased. eg, for a branch with 128 >>> commits including merges, --preserve-merges picks 128 commits and the >>> resulting topology matches the original branch's topology. >>> --rebase-merges picked 183(?) commits in v2.24 and 202 commits in >>> v2.27, and in both cases resulted in a very strange topology. >> >> That's interesting there were some changes to how empty commits and >> upstreamed commits are handled between v2.24 and v2.17, without seeing >> the staring point and the results it's hard to tell what is going on though. >> >> Without seeing some examples it's hard to tell if there is a bug here or >> not though it does sound a bit suspicious. >> >>> Anything else you want to add: >>> Feel free to contact me at joel@xxxxxxxxxxxx for additional details. >> >> You email me directly if there are things you don't want to share on the >> list >> >> Best wishes >> >> Phillip >> >>> I >>> would love to understand if this is by design or a legitimate bug. >>> >>> Please review the rest of the bug report below. >>> You can delete any lines you don't wish to share. >>> >>> >>> [System Info] >>> git version: >>> git version 2.27.0.windows.1 >>> cpu: x86_64 >>> built from commit: 907ab1011dce9112700498e034b974ba60f8b407 >>> sizeof-long: 4 >>> sizeof-size_t: 8 >>> uname: Windows 10.0 18363 >>> compiler info: gnuc: 10.1 >>> libc info: no libc information available >>> >>> >>> [Enabled Hooks] >>>
