errors: raise StateError when push fails because it creates new heads I decided to raise `StateError` here because the local and remote repos are in an incompatible state. I think remote errors (exit code 100) should be when something goes wrong on the remote and there's nothing the user can do. Differential Revision: https://phab.mercurial-scm.org/D9391

errors: raise InputError on early parse error in dispatch I didn't think this would have any effect on the tests, but it does because the catching in `scmutil.callcatch()` still happens. That's because `dispatch` passes in the function that includes the parsing as an argument to that function. I initially used `ConfigError` here but Matt Harbison convinced me to use `InputError`. I think that makes sense since error is not in a config file. Differential Revision: https://phab.mercurial-scm.org/D9387

errors: raise more specifc errors from narrowcommands Differential Revision: https://phab.mercurial-scm.org/D9386

errors: use detailed exit code 50 for StorageError This is done as part of https://www.mercurial-scm.org/wiki/ErrorCategoriesPlan. Differential Revision: https://phab.mercurial-scm.org/D9601

errors: raise InputError if an ambiguous revision id prefix is used It's long bothered me that we include the "00changelog.i" part in a message to the user. This fixes that along with the exit code. Differential Revision: https://phab.mercurial-scm.org/D9600

localrepo: delete obsolete comment about `prefix in repo` raising exception We dropped support for `prefix in repo`, where `prefix` is a hex prefix, in 8b86acc7aa64 (context: drop support for looking up context by ambiguous changeid (API), 2018-04-28), after having deprecated it a while before that. These days you get a `ProgrammingError` instead if you pass in a short nodeid. Differential Revision: https://phab.mercurial-scm.org/D9599

node: import symbols explicitly There is no point in lazy importing mercurial.node, it is used all over the place anyway. So consistently import the used symbols directly. Fix one file using symbols indirectly via mercurial.revlog. Differential Revision: https://phab.mercurial-scm.org/D9480

branching: merge with stable

debugdiscovery: fix swapped heads and roots Patch provided without comment… Differential Revision: https://phab.mercurial-scm.org/D9566

debugdiscovery: display the number of roundtrip used This is a good metric of the complexity of a discovery process. Differential Revision: https://phab.mercurial-scm.org/D9565