It looks like the debian 9 test failures with libssh are the
same underlying issue as https://github.com/wez/wezterm/issues/1262
Poking around in the debug output, and then spelunking through the code,
we can use the `pubkeyacceptedtypes` ssh config option to add the key
type to the list of keys. This doesn't appear to be a documented
option in the current versions of openssh.
I'm not 100% sure that this is right, but it's worth a shot.
Route logging via the `log` crate because on Windows there is
no stderr visible to libssh.
libssh will override any explicitly set options when it parses
the config file, so we need to apply those after we've loaded it.
In the mux layer, we have some code that takes a `Child` and then
does a bit of naughty reaching through the abstraction to get at
the pid/handle of the child so that we can send it signals even
if the child is itself mutably (and thus exclusively) borrowed
for the purposes of waiting.
That worked fine for local processes spawned in the mux, but we also
use LocalPane to wrap around arbitrary `Child`ren, such as Ssh,
that are not local and that don't have a local process id, which
meant that this hack wouldn't work for them.
To make things a bit worse, those ssh ptys were used to ssh2 days
where we didn't have a way to signal the remote process and just
did nothing, leading to confusing situations such as
https://github.com/wez/wezterm/issues/1197
This commit graduates the hack mentioned in the first paragraph
to its own ChildKiller trait. This makes the concept of waiting
for the Child distinct from signalling it and explicitly allows
getting a separate object that can be used for signalling.
With that in place, we're forced to implement something appropriate
for the ssh pty implementations; one in the pty crate itself,
one in wezterm-ssh and the wrapper that we use in the mux crate.
The upshot of this is that the `CloseCurrentPane` action now operates
correctly on panes that were the result of split operations.
@chipsenkbeil: I spotted a latent bug in here that got fixed as
a side effect of this change. For `write_file` and possibly others,
reply.try_send was only called in the case where file_id was valid.
For an invalid id, I think the caller could hang.
Not sure if this was a problem in practice, but I wonder if it might
have contributed to some of the weird state issues you mentioned.
This works, but on macOS, there is a segfault in openssl when the
session is closed... I'm going to try this on Linux to see if it
is consistent behavior and ponder next steps.
The port number is guaranteed to be set in the config parser,
just like for the host and user, so the unwrap is "OK", but it's
less brittle to handle the error consistent with the others here.
I saw this in the stderr logs when the connection was offline:
```
2021-07-17T01:54:28.036Z ERROR wezterm_ssh::session > Failed to write data to channel: Failure while draining incoming flow. Now
what?
2021-07-17T01:54:28.036Z ERROR wezterm_ssh::session > Failed to write data to channel: Failure while draining incoming flow. Now
what?
2021-07-17T01:54:28.142Z ERROR wezterm_ssh::session > Failed to write data to channel: Failure while draining incoming flow. Now
what?
```
This commit propagates the error rather than logging and ignoring it.
In addition, remove a couple of sources of blocking or panicking
that are now unmasked by this.
Possibly the root cause of https://github.com/wez/wezterm/issues/857
