py3: make sure we use bytes in generate-working-copy-states.py

py3: fix keyword arguments handling in hgext/acl.py # skip-blame because we added r'' prefixes

py3: use pycompat.bytestr to convert str returned by getpass.getuser to bytes

py3: add b'' prefixes in test-abort-checkin.t # skip-blame because we just added a b'' prefix.

py3: add b'' prefixes in test-dispatch.py # skip-blame because this is just adding b'' prefixes

cleanup: say goodbye to manifestv2 format This experiment was a bust: we'd hoped for smaller repository sizes, but things got larger. Google ended up rolling out tree manifests in a format that's compatible with the original manifest format, and I believe Facebook is doing the same. This code was never implemented as native speedups, so I'm pretty comfortable saying nobody is using the experimental feature. Let's rip it out. I noticed this code still kicking around because I was investigating a repo corruption issue for timeless. .. bc:: Support for the experimental manifestv2 format has been removed, as it was never completed and failed to meet expectations. Differential Revision: https://phab.mercurial-scm.org/D2393

wireproto: document the wonky push protocol for SSH It took me several minutes to figure out how the "unbundle" protocol worked. It turns out that the SSH protocol handler sends an empty reply that is interpreted as "OK to send" and only then does the client send the bundle payload. On top of that, the response is different depending on whether the operation was successful or not. I nearly pulled out my hair deciphering this. Differential Revision: https://phab.mercurial-scm.org/D2385

wireprototypes: move baseprotocolhandler from wireprotoserver This is needed to prevent a cycle in an upcoming commit. Differential Revision: https://phab.mercurial-scm.org/D2384

sshpeer: defer pipe buffering and stderr sidechannel binding The doublepipe and bufferedinputpipe types facilitate polling multiple pipes without blocking and for automatically forwarding output from the SSH server's stderr pipe to the ui as "remote: " output. This all happens automatically and callers don't need to worry about reading from multiple pipes. An upcoming change to version 2 of the SSH wire protocol will eliminate the use of stderr and move side-channel output into the "main" pipe. The SSH wire protocol will use a pair of unidirectional pipes - just like the HTTP protocol. In this future world, the doublepipe primitive isn't necessary because the stderr pipe won't be used. To prepare for eventually not using doublepipe, we delay the construction of this primitive from immediately after connection establishment to inside construction of the peer instance. The handshake occurs between these two events. So we had to teach the handshake code to read from stderr so any stderr output from the server is still attended to early in the connection lifetime. Differential Revision: https://phab.mercurial-scm.org/D2383

sshpeer: make pipe polling code more explicit "hasbuffer" is a property on our special bufferedinputpipe class. When reading this code, I thought it might have had something special to do properties on built-in types. But "hasbuffer" doesn't appear in the CPython code base for either 2.7 or 3.7, so the answer is no. Let's make the code more explicit about the fact that it deals with our special bufferedinputpipe type. Differential Revision: https://phab.mercurial-scm.org/D2382