branchmap: don't add branch entries if there are no heads We definitely don't want any empty entries to be present in repo.branchmap() just for the sake of not breaking test-notify.t. No test changes required because the previous patch made notify extension to not raise any tracebacks in case of RepoLookupErrors. Differential Revision: https://phab.mercurial-scm.org/D12135

notify: don't produce errors if a revision is not found Notify extension has a way to only subscribe to a specific revset, such as "branch(foo)". Before this patch, when there was no branch with that name, it would produce a traceback saying "unknown revision: foo". With this patch it would no longer do that, and instead it'll assume there are no revisions that match this revset. I think this patch is an improvement in general, but there's a reason I'm sending it now. test-notify.t has a test case where it obsoletes the only revision on a branch, and previously that wouldn't produce any complications, because head computation wasn't obsolescence-aware. Now if the only revision on a branch is obsolete, repo should not see that branch at all. That branch will still be present in branchcache (with an empty list of revisions) until the next patch. Differential Revision: https://phab.mercurial-scm.org/D12134

narrow: allow merging non-conflicting change outside of the narrow spec We use the mergestate to carry information about these merge action and reprocess them at commit time to apply the necessary update. The dirstate itself is never affected and remains "pure", with content only in the narrow-spec. This file involved in such merge are therefor not listed in `hg status`. The current testing is based on a modification of the previous testing, that refused to do such merges. As a result it is a bit simple and more extensive code and testing testing will have to be introduced later. I am planning to do this extra testing, soon. In addition, this only works for flat manifest. Support for tree manifest will need more work. I am not currently planning to do this work. Differential Revision: https://phab.mercurial-scm.org/D12119

merge-actions: add some information about the "changes" the action do This will be useful when processing merges action outside of the narrow-spec. "support" outside of narrow file on commit Differential Revision: https://phab.mercurial-scm.org/D12118

merge-actions: have an attribute for narrow safetiness This allow the core doing narrow filtering to process action without explicitely listing all possible actions. This is important to make the actions system more flexible in the future. Differential Revision: https://phab.mercurial-scm.org/D12117

merge-actions: add an explicite "no_op" attribute This make the MergeAction smarter and able to describe themself. This is useful to help introducing more MergeAction object that better the complexity of the situation. Differential Revision: https://phab.mercurial-scm.org/D12116

merge-actions: gather all created action into a set This is mostly to demonstrate we can do this before we start adding more specialized set. Differential Revision: https://phab.mercurial-scm.org/D12115