problem with using backspace for Chinese characters（one char of 2 bytes） about ssh-chat HOT 9 CLOSED

This might not be entirely supported yet, since the EraseNPreviousChars(n) function erases N amount of characters at a time. You can see how the backspace function is implemented a few lines down on that file here

I am not super familiar enough with the keyboard I/O code personally, but I don't think ssh-chat is contextually aware of what your user locale is going to be exactly. The server side is responsible for key inputs and rendering the readline functionality, but its probable that ssh-chat doesn't have enough contextual information for each user to be able to do this. To ssh-chat, when you enter a 2-byte character, ssh-chat sees exactly 2-bytes. It doesn't process whether or not that might be a rune, it only handles it at an individual byte level.

from ssh-chat.

Hi @jonnyliang, I'm not able to reproduce this. It may be an issue with your terminal, or compatibility between your terminal and how we handle unicode character width counting:

What terminal are you using? Could you try a modern terminal like kitty or alacritty?

from ssh-chat.

I reproduce it. That is terminal compatibility issue.
In alacritty,it works perfect.
In cmd/powershell/windows temiernal, It will leave char after chinese in buffer(I guess)

(Delete chinese from the end of input)

(Delete chinese from the middle of input.And enf of input " g g" is display after delete)

Versions

Client version: Ubuntu 22.04
Server version:Windows 11
ssh-chat version: 1.10,1.11-rc5

from ssh-chat.

Yea, that's a terminal issue unfortunately, they don't count character width the same way as modern terminals. There's no way to support both.

from ssh-chat.

Hi @jonnyliang, I'm not able to reproduce this. It may be an issue with your terminal, or compatibility between your terminal and how we handle unicode character width counting:

What terminal are you using? Could you try a modern terminal like kitty or alacritty?

You are right, this a terminal issue unfortunately, it will leave half of a char when I using XSHELL 5. it work by using alacritty! thanks！

from ssh-chat.

Yea, that's a terminal issue unfortunately, they don't count character width the same way as modern terminals. There's no way to support both.
By the way, I fixed the problem on my local code as below, it seems work well on alacritty and XSHELL，but I not sure its ok.

//
_, _, left, _ := t.moveCursorToPos(t.pos)
copy(t.line[t.pos:], t.line[n+t.pos:])
t.line = t.line[:len(t.line)-n]
if t.echo {
t.writeLine(t.line[t.pos:])
for i := 0; i < left; i++ {
t.queue(space)
}
t.advanceCursor(left)
....

from ssh-chat.

reproduce on alacritty~!

from ssh-chat.

If you have a patch that fixes this and doesn't break other things, please make a PR and I'll take a look. :)

from ssh-chat.

I just modified content of two functions，Hope for better solution！

ssh-chat/sshd/terminal/terminal.go

func (t *Terminal) moveCursorToPos(pos int) (up, down, left, right int) {
  ...
  return up, down, left, right
}

func` (t *Terminal) eraseNPreviousChars(n int) {
        if n == 0 {
                return
        }

        if t.pos < n {
                n = t.pos
        }
        t.pos -= n
        //t.moveCursorToPos(t.pos)
       //-----------fixed begin------------------------------ 
        up, _, left, _ := t.moveCursorToPos(t.pos) 
        if left ==0{
            if up == 1{left =up}
        }
        //-----------fixed end------------------------------ 
        copy(t.line[t.pos:], t.line[n+t.pos:])
        t.line = t.line[:len(t.line)-n]
        if t.echo {
                t.writeLine(t.line[t.pos:])
                for i := 0; i < left; i++ { // left  replace n 
                        t.queue(space)
                }
                t.advanceCursor(left)
                t.moveCursorToPos(t.pos)
        }
}

from ssh-chat.