rust-chg: modernize entry function Finally the entire build passes. There's a bug that run() no longer waits for the spawned pager, which will be fixed by the next patch. Differential Revision: https://phab.mercurial-scm.org/D8448

rust-chg: reimplement locator by using async/await and tokio-0.2 connect_spawned() is rewritten from scratch by using std::process. Before, it would select completion of either connection or server process. New code could be implemented as such, but it's much simpler to occasionally run try_wait() to detect server death. Differential Revision: https://phab.mercurial-scm.org/D8447

rust-chg: reimplement ChgClientExt as ChgClient wrapper ChgClient is no longer an extension trait because: a. Client object is not consumed and recreated in future-0.3 world, which unblocks writing a simple wrapper struct. b. async fn isn't allowed in trait. Overall, the API should become simpler. Differential Revision: https://phab.mercurial-scm.org/D8446

rust-chg: reimplement run_command operation as async function The crafted state machine is no longer needed thanks to async/await. The state machine is basically rewritten as follows: - Ready(..) -> return .. - PollAgain(..) -> run .. and await - Err(..) -> return Err(..) Differential Revision: https://phab.mercurial-scm.org/D8445

rust-chg: reimplement uihandler by using async-trait and tokio-0.2 We no longer have to consume self and arguments. Differential Revision: https://phab.mercurial-scm.org/D8444

rust-chg: have attach_io() simply take reference of AsRawFd object We no longer have to deal with the restriction of the Future type. Before, these file objects couldn't be references and that's the only reason why we had to make stderr an Option<T>. This fixes future type deduction issue of stderr = None, where rustc would complain that T of Option<T> couldn't be deduced. Differential Revision: https://phab.mercurial-scm.org/D8443

rust-chg: reimplement attach_io operation as async function In short, MessageLoop<Connection> was redesigned as Protocol<Connection>, and the protocol methods no longer consume self. API changes are briefly documented in the following page: https://docs.rs/tokio-hglib/0.3.0/tokio_hglib/struct.Protocol.html Differential Revision: https://phab.mercurial-scm.org/D8442

rust-chg: upgrade to futures-0.3 based libraries And do some trivial fixes: - BytesMut::put_u32_be() -> put_u32() - tokio_process -> tokio::process, CommandExt -> Command, spawn_async() -> spawn(), stdin() -> stdin - tokio_timer::sleep() -> tokio::time::delay_for() Differential Revision: https://phab.mercurial-scm.org/D8441

rust-chg: exclude futures-dependent modules from build and break things It's impractical to upgrade the codebase incrementally since futures 0.1 and 0.3 APIs are fundamentally different. So this patch temporarily excludes futures-dependent modules from the build. These modules will be upgraded and re-enabled one by one. Differential Revision: https://phab.mercurial-scm.org/D8440

commit: tell user what to do with .hg/last-message.txt I have always assumed that the message will be reused by the next `hg commit`, but it seems it's just silently dropped on the next commit. Let's try to be more helpful by telling the user that they have to manually tell hg to reuse it. The file will still be lost if the user runs some other operation in between (like a non-in-memory rebase). That will be fixed once we've switched all operations to be in-memory :) I didn't include `$(hg root)/` in the path in the message to the user because that would have made the message too long. Hopefully the user will figure that part out themselves. Differential Revision: https://phab.mercurial-scm.org/D8463

test-check-rust-format: specify --edition=2018 rustfmt doesn't read Cargo.toml unless it's executed by cargo. https://github.com/rust-lang/rustfmt#rusts-editions

convert: use bytes for value in extra dict The keys and values of the extra dict are expected to be bytes. Before this fix, there was a crash in mercurial.changelog.encodeextra().