Kitty keyboard protocol doesn't work with foot >=v1.17.0

[postsolar]

Summary

See https://codeberg.org/dnkl/foot/issues/1642

From what I understand it's a crossterm's responsibility?

Reproduction Steps

I tried this:

0. Have a keys.normal.s-backspace mapping
1. hx
2. s-backspace
3. Doesn't work

I expected this to happen:

Work

Instead, this happened:

No work

Helix log

~/.cache/helix/helix.log

please provide a copy of `~/.cache/helix/helix.log` here if possible, you may need to redact some of the lines

Platform

Linux

Terminal Emulator

foot version: 1.17.0 +pgo +ime +graphemes -assertions

Installation Method

flake

Helix Version

24.03-125-gf031932f

[the-mikedavis]

I believe this is a foot bug. Shift+backspace gives a backspace key event with a shift modifier for me on Kitty but not foot, although I was testing against foot 1.14.0. To dig deeper you can use crossterm's event-read example (clone crossterm and cargo run --example event-read in the crossterm repo directory). You can modify the flags in that example to match what we select:

helix/helix-tui/src/backend/crossterm.rs

Lines 161 to 164 in 1245760

	PushKeyboardEnhancementFlags(
	KeyboardEnhancementFlags::DISAMBIGUATE_ESCAPE_CODES
	| KeyboardEnhancementFlags::REPORT_ALTERNATE_KEYS
	)

[postsolar]

Yes what I report is consistent with crossterm (given the same flags as Helix) and yes it's definitely foot-specific, but as expressed by @dnkl in https://codeberg.org/dnkl/foot/issues/1642#issuecomment-1660461 it's intended behavior rather than a bug.

It's weird it doesn't work for you on foot 1.14.0 — I use the commit directly before the commit that introduced this problem (so d3b348a5b183b0e6295dc985b1d5dcd939cb5c6e), which would correspond to 1.16.2, and it works correctly for me.

I tried simply adding more flags to Helix, and it did solve the issue at hand, but, not unexpectedly, raised some other critical problem (I don't remember what it was exactly).

[postsolar]

Seems to be the same issue with alacritty 0.13.2. Works fine with the wider set of flags, but not with the set of flags used by Helix.