rebase: remove some redundant setting of dirstate parents Since we're now setting the dirstate parents to its correct values from the beginning (right after `merge.update()`), we usually don't need to set them again before committing. The only case we need to care about is when committing collapsed commits. So we can remove the `setparents()` calls just before committing and add one only for the collapse case. Differential Revision: https://phab.mercurial-scm.org/D7828

rebase: don't use rebased node as dirstate p2 (BC) When rebasing a node, we currently use the rebased node as p2 in the dirstate until just before we commit it (we then change to the desired parents). This p2 is visible to the user when the rebase gets interrupted because of merge conflicts. That can be useful to the user as a reminder of which commit is currently being rebased, but I believe it's incorrect for a few reasons: * I think the dirstate parents should be the ones that will be set when the commit is created. * I think having two parents means that you're merging those two commits, but when rebasing, you're generally grafting, not merging. * When rebasing a merge commit, we should use the two desired parents as dirstate parents (and we clearly can't have the rebased node as a third dirstate parent). * `hg graft` (and `hg update --merge`) sets only one parent and `hg rebase` should be consistent with that. I realize that this is a somewhat large user-visible change, but I think it's worth it because it will simplify things quite a bit. Differential Revision: https://phab.mercurial-scm.org/D7827

rebase: stop relying on having two parents to resume rebase I'm about to make it so we don't have two parents when a rebase is interrupted (unless we're just rebasing on a merge commit). The code for detecting if we're resuming a rebase relied on having two parents, so this patch rewrites that to instead set a boolean when we resume. Note that `self.resume` in the new condition implies `not self.inmemory` (rebase cannot be resumed in memory), so that's why that part can be omitted. Differential Revision: https://phab.mercurial-scm.org/D7826

graphlog: use '%' for other context in merge conflict This lets the user more easily find the commit that is involved in the conflict, such as the source of `hg update -m` or the commit being grafted by `hg graft`. Differential Revision: https://phab.mercurial-scm.org/D8043

tests: add `hg log -G` output when there are merge conflicts The next commit will change the behavior for these. I've used slightly different commands in the different tests to match the surrounding style. Differential Revision: https://phab.mercurial-scm.org/D8042

revset: add a revset for parents in merge state This may be particularly useful soon, when I'm going to change how `hg rebase` sets its parents during conflict resolution. Differential Revision: https://phab.mercurial-scm.org/D8041

tests: add test of rebase with conflict in merge commit It doesn't seem like we had any tests of this. I think it's pretty weird that the two parents we're merging are not the working copy parents during the conflict resolution. Differential Revision: https://phab.mercurial-scm.org/D7824

rebase: always be graft-like, not merge-like, also for merges Rebase works by updating to a commit and then grafting changes on top. However, before this patch, it would actually merge in changes instead of grafting them in in some cases. That is, it would use the common ancestor as base instead of using one of the parents. That seems wrong to me, so I'm changing it so `defineparents()` always returns a value for `base`. This fixes the bad behavior in test-rebase-newancestor.t, which was introduced in 65f215ea3e8e (tests: add test for rebasing merges with ancestors of the rebase destination, 2014-11-30). The difference in test-rebase-dest.t is because the files in the tip revision were A, D, E, F before this patch and A, D, F, G after it. I think both files should ideally be there. Differential Revision: https://phab.mercurial-scm.org/D7907

nodemap: update the index with the newly written data (when appropriate) If we are to use mmap to read the nodemap data, and if the python code is responsible for the IO, we need to refresh the mmap after each write and provide it back to the index. We start this dance without the mmap first. Differential Revision: https://phab.mercurial-scm.org/D7893

nodemap: never read more than the expected data amount Since we are tracking this number we can use it to detect corrupted rawdata file and to only read the correct amount of data when possible. Differential Revision: https://phab.mercurial-scm.org/D7892