fix(login): send OpenSSH-like PTY modes and release v0.12.1

CHANGELOG.md

@@ -7,6 +7,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.12.1] - 2026-08-30
+
+### Fixed
+
+- `sshx login` requested a PTY with only `ECHO`/`ECHOCTL` set, so remote zsh
+  (and plugins such as zsh-autosuggestions) could mis-measure UTF-8 prompt
+  width and reprint each typed character. Login now sends OpenSSH-like cooked
+  UTF-8 tty modes and forwards `LANG`/`LC_*`/`COLORTERM` when the server
+  allows it.
+
 ## [0.12.0] - 2026-08-28
 
 ### Changed

docs/troubleshooting.md

@@ -98,6 +98,38 @@ sshx -h=prod-web --dry-run --json "sudo rm -rf /"
 
 If a privileged or destructive command is genuinely intended, review it, record the reason, and use `--force` only for that invocation.
 
+## Login Types Extra Characters
+
+Symptoms: after `sshx login`, each keystroke appears more than once. Extra
+copies are often dim, gray, or pink. Tab completion or zsh-autosuggestions
+look garbled.
+
+Update sshx first. Older builds sent a sparse PTY mode list (echo only), which
+can make remote zsh reprint typed characters.
+
+If it still happens in the Cursor or VS Code integrated terminal, that
+emulator's **local echo** (type-ahead) draws predicted keystrokes in a dim
+color. It turns itself off for `vim`/`tmux`, but not for `sshx`, and it
+fights zsh-autosuggestions:
+
+```json
+{
+  "terminal.integrated.localEchoExcludePrograms": [
+    "vim",
+    "vi",
+    "nano",
+    "tmux",
+    "ssh",
+    "sshx"
+  ]
+}
+```
+
+To disable the feature entirely: `"terminal.integrated.localEchoEnabled": false`.
+
+Compare with `ssh` in the **same** terminal. If OpenSSH glitches too, this is
+the emulator, not sshx.
+
 ## Script Hangs
 
 Set a timeout:

docs/zh/troubleshooting.md

@@ -96,6 +96,31 @@ sshx -h=prod-web --dry-run --json "sudo rm -rf /"
 
 如果特权或破坏性命令确实是预期操作，先审阅、记录原因，再只对这一次使用 `--force`。
 
+## Login 后输入一个字母出现好几个
+
+症状：`sshx login` 之后每按一个键，屏幕上会出现多个相同字符；多出来的往往是暗色、灰色或粉色。Tab 补全或 zsh-autosuggestions 也会错乱。
+
+先升级 sshx。旧版本申请 PTY 时只设置了 echo，远端 zsh 可能把提示符宽度算错，从而把刚输入的字符又画一遍。
+
+若升级后在 Cursor / VS Code 集成终端里仍复现，多半是终端的 **local echo**（预显示）。它会给 `vim`/`tmux` 自动关掉，但不会给 `sshx` 关，于是和 zsh-autosuggestions 叠在一起：
+
+```json
+{
+  "terminal.integrated.localEchoExcludePrograms": [
+    "vim",
+    "vi",
+    "nano",
+    "tmux",
+    "ssh",
+    "sshx"
+  ]
+}
+```
+
+彻底关掉该功能：`"terminal.integrated.localEchoEnabled": false`。
+
+在**同一个**终端里对比 `ssh`：如果 OpenSSH 也花屏，问题在终端模拟器，不在 sshx。
+
 ## 脚本卡住
 
 设置 timeout：

internal/sshclient/login.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"os"
 
+	"golang.org/x/crypto/ssh"
 	"golang.org/x/term"
 )
 
@@ -33,3 +34,70 @@ func (c *SSHClient) Login() error {
 	}
 	return c.loginSession()
 }
+
+func loginTermName() string {
+	if name := os.Getenv("TERM"); name != "" {
+		return name
+	}
+	return "xterm-256color"
+}
+
+// loginPtyModes is the cooked UTF-8 tty state OpenSSH typically sends with
+// pty-req. A sparse ECHO-only list leaves IUTF8/ONLCR/ICRNL at the PTY
+// allocator default, which on some hosts makes zsh/zle and autosuggestions
+// reprint typed characters.
+func loginPtyModes(sudo bool) ssh.TerminalModes {
+	echo := uint32(1)
+	echoCtl := uint32(1)
+	if sudo {
+		echo = 0
+		echoCtl = 0
+	}
+	return ssh.TerminalModes{
+		ssh.VINTR:         3,
+		ssh.VQUIT:         28,
+		ssh.VERASE:        127,
+		ssh.VKILL:         21,
+		ssh.VEOF:          4,
+		ssh.VSTART:        17,
+		ssh.VSTOP:         19,
+		ssh.VSUSP:         26,
+		ssh.IGNPAR:        0,
+		ssh.INLCR:         0,
+		ssh.IGNCR:         0,
+		ssh.ICRNL:         1,
+		ssh.IUCLC:         0,
+		ssh.IXON:          1,
+		ssh.IXANY:         1,
+		ssh.IXOFF:         0,
+		ssh.IMAXBEL:       1,
+		ssh.IUTF8:         1,
+		ssh.ISIG:          1,
+		ssh.ICANON:        1,
+		ssh.ECHO:          echo,
+		ssh.ECHOE:         1,
+		ssh.ECHOK:         1,
+		ssh.ECHONL:        0,
+		ssh.IEXTEN:        1,
+		ssh.ECHOCTL:       echoCtl,
+		ssh.ECHOKE:        1,
+		ssh.OPOST:         1,
+		ssh.ONLCR:         1,
+		ssh.OCRNL:         0,
+		ssh.CS8:           1,
+		ssh.PARENB:        0,
+		ssh.TTY_OP_ISPEED: 14400,
+		ssh.TTY_OP_OSPEED: 14400,
+	}
+}
+
+func loginEnvVars() [][2]string {
+	keys := []string{"LANG", "LC_ALL", "LC_CTYPE", "COLORTERM"}
+	out := make([][2]string, 0, len(keys))
+	for _, key := range keys {
+		if val := os.Getenv(key); val != "" {
+			out = append(out, [2]string{key, val})
+		}
+	}
+	return out
+}

internal/sshclient/login_test.go

@@ -32,6 +32,72 @@ func TestLoginRequiresConnection(t *testing.T) {
 	}
 }
 
+func TestLoginPtyModesInteractiveLooksLikeOpenSSH(t *testing.T) {
+	modes := loginPtyModes(false)
+	want := map[uint8]uint32{
+		ssh.ECHO:    1,
+		ssh.ECHOCTL: 1,
+		ssh.IUTF8:   1,
+		ssh.ICRNL:   1,
+		ssh.ONLCR:   1,
+		ssh.ICANON:  1,
+		ssh.ISIG:    1,
+		ssh.OPOST:   1,
+		ssh.CS8:     1,
+		ssh.VERASE:  127,
+		ssh.VINTR:   3,
+	}
+	for key, val := range want {
+		if modes[key] != val {
+			t.Fatalf("loginPtyModes(false)[%d] = %d, want %d", key, modes[key], val)
+		}
+	}
+}
+
+func TestLoginPtyModesSudoDisablesEchoKeepsUTF8(t *testing.T) {
+	modes := loginPtyModes(true)
+	if modes[ssh.ECHO] != 0 || modes[ssh.ECHOCTL] != 0 {
+		t.Fatalf("sudo login PTY must start with echo off, got ECHO=%d ECHOCTL=%d",
+			modes[ssh.ECHO], modes[ssh.ECHOCTL])
+	}
+	if modes[ssh.IUTF8] != 1 || modes[ssh.ONLCR] != 1 {
+		t.Fatalf("sudo login PTY must still be a UTF-8 cooked terminal, got IUTF8=%d ONLCR=%d",
+			modes[ssh.IUTF8], modes[ssh.ONLCR])
+	}
+}
+
+func TestLoginTermNameUsesTERM(t *testing.T) {
+	t.Setenv("TERM", "xterm-ghostty")
+	if got := loginTermName(); got != "xterm-ghostty" {
+		t.Fatalf("loginTermName() = %q, want xterm-ghostty", got)
+	}
+	t.Setenv("TERM", "")
+	if got := loginTermName(); got != "xterm-256color" {
+		t.Fatalf("loginTermName() = %q, want xterm-256color", got)
+	}
+}
+
+func TestLoginEnvVarsForwardsLocale(t *testing.T) {
+	t.Setenv("LANG", "en_US.UTF-8")
+	t.Setenv("LC_ALL", "")
+	t.Setenv("LC_CTYPE", "C.UTF-8")
+	t.Setenv("COLORTERM", "truecolor")
+	got := loginEnvVars()
+	want := [][2]string{
+		{"LANG", "en_US.UTF-8"},
+		{"LC_CTYPE", "C.UTF-8"},
+		{"COLORTERM", "truecolor"},
+	}
+	if len(got) != len(want) {
+		t.Fatalf("loginEnvVars() = %v, want %v", got, want)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("loginEnvVars()[%d] = %v, want %v", i, got[i], want[i])
+		}
+	}
+}
+
 func TestLoginWithoutTTY(t *testing.T) {
 	if !InteractiveLoginSupported() {
 		t.Skip("login session is not implemented on this platform")

internal/sshclient/login_unix.go

@@ -28,24 +28,10 @@ func (c *SSHClient) loginSession() error {
 
 	fd := int(os.Stdin.Fd())
 	width, height := terminalSize(fd)
-	termName := os.Getenv("TERM")
-	if termName == "" {
-		termName = "xterm-256color"
-	}
-
-	echo := uint32(1)
-	if c.config.LoginUseSudo {
-		echo = 0
-	}
-	modes := ssh.TerminalModes{
-		ssh.ECHO:          echo,
-		ssh.ECHOCTL:       0,
-		ssh.TTY_OP_ISPEED: 14400,
-		ssh.TTY_OP_OSPEED: 14400,
-	}
-	if ptyErr := session.RequestPty(termName, height, width, modes); ptyErr != nil {
+	if ptyErr := session.RequestPty(loginTermName(), height, width, loginPtyModes(c.config.LoginUseSudo)); ptyErr != nil {
 		return fmt.Errorf("failed to request login PTY: %w", ptyErr)
 	}
+	forwardLoginEnv(session)
 
 	stdin, err := session.StdinPipe()
 	if err != nil {
@@ -86,6 +72,12 @@ func (c *SSHClient) loginSession() error {
 	return waitErr
 }
 
+func forwardLoginEnv(session *ssh.Session) {
+	for _, kv := range loginEnvVars() {
+		_ = session.Setenv(kv[0], kv[1]) //nolint:errcheck // sshd may reject env; the session must still start
+	}
+}
+
 func terminalSize(fd int) (width, height int) {
 	width, height, err := term.GetSize(fd)
 	if err != nil || width <= 0 || height <= 0 {