fix: incorrect parsing on WSL due to buffering of osc esc sequences

[rgodha24]

it passes all tests and fixes the repro described in the bubbletea issue (first link below).

related:

• https://github.com/charmbracelet/bubbletea/issues/1440
• https://github.com/charmbracelet/bubbletea/issues/1406
• https://github.com/charmbracelet/x/pull/497
• https://github.com/charmbracelet/x/commit/39faa120bfa597a373e044bd1ebe8f36d2d822f4

my conversation with o3 to diagnose this issue: https://gist.github.com/rgodha24/3c6934b9ec94df4ab0bf75588d1042dc (t3.chat doesnt have share links yet)

NOTE: this is completely vibe coded. I would not get mad at all if this is closed bc of subpar code quality

[lrstanley]

Can confirm that this seems to fix the issue for me locally with WSL2 + Windows Terminal. Still testing on other terminals, but looks promising.

EDIT: seems as though with WezTerm & WSL2, and Hyper (js) & WSL2 (only other terminal emulators I have locally), neither seem to receive the background color message still. Though, they also don't seem to respond to cat | printf '\x1b]11;?\x07' so I'm not sure if they support the query. @rgodha24 does it work for you with WezTerm?

[rgodha24]

unfortunately i can only test with windows terminal because of work computer restrictions.

EDIT: the below probably isnt true. one of the original issues that led me down this rabbithole mentioned they were having this issue on Wezterm as well (https://github.com/sst/opencode/issues/127#issuecomment-2978440226). @lrstanley would you be able to test the repro in the first issue linked in the description on wezterm?

from my very limited googling, it seems like wezterm does not support the osc 11 query, but this could be incorrect.

[lrstanley]

unfortunately i can only test with windows terminal because of work computer restrictions.

EDIT: the below probably isnt true. one of the original issues that led me down this rabbithole mentioned they were having this issue on Wezterm as well (sst/opencode#127 (comment)). @lrstanley would you be able to test the repro in the first issue linked in the description on wezterm?

from my very limited googling, it seems like wezterm does not support the osc 11 query, but this could be incorrect.

Not sure which repro you're referring to, unless you mean running opencode itself on that specific commit (before the patch was implemented?)

I did see https://github.com/wezterm/wezterm/issues/5899 -- and although this is supported through ConPTY now I think, wezterm hasn't released in a while and might depend on something older with such an old build.

Unless there is a usecase where we know it should return a response that I can test with, I'd say it's probably fine to continue with this fix, unless someone else notices specific issues.

[rgodha24]

Not sure which repro you're referring to, unless you mean running opencode itself on that specific commit (before the patch was implemented?)

would you be able to try this @lrstanley ?

package main

import (
	"fmt"
	"image/color"
	"log"
	"os"
	"path/filepath"

	tea "github.com/charmbracelet/bubbletea/v2"
	"github.com/charmbracelet/x/input"
)

type model struct {
	bgColor    color.Color
	keypresses string
	logpath    string
}

func (m model) Init() tea.Cmd {
	return tea.RequestBackgroundColor
}

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	log.Printf("Received msg: %#v with type %T", msg, msg)

	switch msg := msg.(type) {
	case tea.BackgroundColorMsg:
		// this never happens on windows terminal
		log.Printf("got a BackgroundColorMsg with color %#v", msg.Color)
		m.bgColor = msg.Color
		return m, nil
	case input.UnknownEvent:
		log.Printf("got an unknown event '%v'", msg.String())
		return m, nil

	case tea.KeyPressMsg:
		switch keypress := msg.String(); keypress {
		case "q", "ctrl+c":
			return m, tea.Quit
		default:
			m.keypresses += msg.String()
			return m, nil
		}
	}

	return m, nil
}

func (m model) View() string {
	return fmt.Sprintf("logging to %s\nkeypresses: %s\nbg color: %#v\n", m.logpath, m.keypresses, m.bgColor)
}

func main() {
	logpath := filepath.Join(os.TempDir(), "repro.log")
	f, err := tea.LogToFile(logpath, "")
	if err != nil {
		fmt.Println("fatal:", err)
		os.Exit(1)
	}
	defer f.Close()

	if _, err := tea.NewProgram(model{logpath: logpath}).Run(); err != nil {
		fmt.Println("Error running program:", err)
		os.Exit(1)
	}
}

[lrstanley]

would you be able to try this @lrstanley ?

// [...]

That's effectively what my testing has already been doing. WezTerm/Hyper, no background color received (but doesn't look like they support it from OSC query testing). Works on Windows Terminal + WSL2, with the x/input fix.

[rgodha24]

@aymanbagabas any movement on this issue?

[lrstanley]

I think it's pending primarily due to the new https://github.com/charmbracelet/ultraviolet package, that I think they're about to switch to using in the v2-exp branches of bubbletea/lipgloss. I haven't had time to confirm yet if it solves the issues though.

[lrstanley]

FYI, I think the issue still occurs with the ultraviolet implementation, due to the same issues outlined here (the escape sequences caught at the end of 1 buffer don't get cleanly grouped into the next received buffer). Working with Ayman on the issue.