Two new options:
- server option "exit-unattached" makes the server exit when no clients
are attached, even if sessions are present;
- session option "destroy-unattached" destroys a session once no clients
are attached to it.
These are useful for preventing tmux remaining in the background where
it is undesirable and when using tmux as a login shell to keep a limit
on new sessions.
Use UTF-8 line drawing characters on UTF-8 terminals. Fixes some stupid
terminals (I'm looking at you, putty) which disable the vt100 ACS mode
switching sequences in UTF-8 mode.
Also on terminals without ACS at all, use ASCII equivalents where
obvious.
Add -n and -p flags to switch-client to move to the next and previous
session (yes, it doesn't match window/pane, but so what, nor does
switch-client).
Based on a diff long ago from "edsouza".
Do not call event_del() for signals after fork(), just use sigaction()
directly instead - calling libevent functions after fork() w/o
event_reinit() is a bad idea, even if in this case it was harmless.
Change the way backoff works. Instead of stopping reading from the pty
when the client tty backs up too much, just stop updating the tty and
only update the internal screen. Then when the tty recovers, force a
redraw.
This prevents a dodgy client from causing other clients to go into
backoff while still allowing tmux to be responsive (locally) when seeing
lots of output.
When changing so that the client passes its stdout and stderr as well as
stdin up to the server, I forgot one essential point - the tmux server
could now be both the producer and consumer. This happens when tmux is
run inside tmux, as well as when piping tmux commands together.
So, using stdio(3) was a bad idea - if sufficient data was written, this
could block in write(2). When that happened and the server was both
producer and consumer, it deadlocks.
Change to use libevent bufferevents for the client stdin, stdout and
stderr instead. This is trivial enough for output but requires a
callback mechanism to trigger when stdin is finished.
This relies on the underlying polling mechanism for libevent to work
with whatever devices to which the user could redirect stdin, stdout or
stderr, hence the change to use poll(2) over kqueue(2) for tmux.
Don't return if in the current window since we may want to report a bell
(if bell-action any/current), just clear the flag so the status line
doesn't show the bell.
