See the changelog additions for user-visible changes.
Since we enable/disable terminal protocols whenever we pass terminal ownership,
tests can no longer run in parallel on the same terminal.
For the same reason, readline shortcuts in the gdb REPL will not work anymore.
As a remedy, use gdbserver, or lobby for CSI u support in libreadline.
Add sleep to some tests, otherwise they fall (both in CI and locally).
There are two weird failures on FreeBSD remaining, disable them for now
https://github.com/fish-shell/fish-shell/pull/10359/checks?check_run_id=23330096362
Design and implementation borrows heavily from Kakoune.
In future, we should try to implement more of the kitty progressive
enhancements.
Closes#10359
Prior to 1811a2d, the return value for negative return codes was UB and I'd
witnessed both expected cases like -256 mapping to a $status of 0 and unexpected
cases like a return value of -1 mapping to a $status of 0. As such, this doesn't
test just one fixed return value but the entire range from negative multiples of
256 all the way down (rather, up!) to -1.
Currently, if a "return" is given outside of a function, we'd just
throw an error.
That always struck me as a bit weird, given that scripts can also
return a value.
So simply let "return" outside also exit the script, kinda like "exit"
does.
However, unlike "exit" it doesn't quit an interactive shell - it seems
weird to have "return" do that as well. It sets $status, so it can be
used to quickly set that, in case you want to test something.
