Mercurial: Changelog

tests: test using both versions of SSH protocol Now that the version 2 of the SSH protocol is usable in core, we can start actively testing it more widely outside of low-level protocol tests. We add #testcases variants to a handful of tests so we exercise both version 1 and version 2 of the SSH protocol when testing. This will allow us to more easily find regressions and variances as protocol 2 is developed. It will also make it easier to continue testing with protocol version 1 once version 2 is enabled by default. There are a handful of tests using ssh:// that should also gain test variances. One - test-push-race.t - already has a #testcases. This would require combinatorial cases. I didn't want to go down that rabbit hole, so that test is unchanged. Thinking aloud, there is probably an opportunity to automatically run tests with multiple server/protocol implementations. Ideally any test that performed server interaction would run with all supported server implementations and protocols so we could find variances between servers and protocols. But this has been a long-standing issue with our test harness. I don't think it is an easily solved problem. But it would be nice... Differential Revision: https://phab.mercurial-scm.org/D2206

sshpeer: log remote capabilities after protocol upgrade This helps reduce variance with version 1 and will help prevent test output divergence as we start testing protocol version 2 more widely. Differential Revision: https://phab.mercurial-scm.org/D2205

wireprotoserver: handle SSH protocol version 2 upgrade requests This commit teaches the SSH server to recognize the "upgrade" request line that clients send when they wish to switch the channel to version 2 of the SSH protocol. Servers don't honor upgrade requests unless an experimental config option is set. Since the built-in server now supports upgrade requests, our test server to test the handshake has been deleted. Existing tests use the built-in server and their output doesn't change. The upgrade is handled in our state machine. The end result is a bit wonky, as the server transitions back to version 1 state immediately after upgrading. But this will change as soon as version 2 has an actual protocol that differs from version 1. Tests demonstrating that the new server is a bit more strict about the upgrade handshake have been added. Differential Revision: https://phab.mercurial-scm.org/D2204

wireprotoserver: move SSH server operation to a standalone function The server-side processing logic will soon get a bit more complicated in order to handle protocol switches. We will use a state machine to help make the transitions clearer. To prepare for this, we move SSH server operation into a standalone function. We structure it as a very simple state machine. It only has two states for now, with one state containing the bulk of the logic. But things will evolve shortly. Differential Revision: https://phab.mercurial-scm.org/D2203