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
This is the last remnant of the old percent expansion.
It has the downsides of it, in that it is annoying to combine with
anything:
```fish
echo %self/foo
```
prints "%self/foo", not fish's pid.
We have introduced $fish_pid in 3.0, which is much easier to use -
just like a variable, because it is one.
If you need backwards-compatibility for < 3.0, you can use the
following shim:
```fish
set -q fish_pid
or set -g fish_pid %self
```
So we introduce a feature-flag called "remove-percent-self" to turn it
off.
"%self" will simply not be special, e.g. `echo %self` will print
"%self".
