If a binding was input starting with "\e", it's usually a raw control sequence.
Today we display the canonical version like:
bind --preset alt-\[,1,\;,5,C foo
even if the input is
bind --preset \e\[1\;5C foo
Make it look like the input again. This looks more familiar and less
surprising (especially since we canonicalize CSI to "alt-[").
Except that we use the \x01 representation instead of \ca because the
"control" part can be confusing. We're inside an escape sequence so it seems
highly unlikely that an ASCII control character actually comes from the user
holding the control key.
The downside is that this hides the canonical version; it might be surprising
that a raw-escape-sequence binding can be erased using the new syntax and
vice versa.
We don't yet support all keys from
https://sw.kovidgoyal.net/kitty/keyboard-protocol/#functional-key-definitions
Instead of displaying a private-use character, show the character code;
this can be used to map the key even if we don't know a name for it.
bind \uE011 'echo print screen'
bind ctrl-\uE011 'echo do control + print screen'
Note that it's also possible to mape the raw CSI u sequence, like
bind \e\[57361u 'echo print screen'
but we should not encourage that syntax because it does not allow adding
the modifiers like ctrl.
Of course leaking the PUA character code is not ideal.
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
