From 42e77e2a699ab0eb2f27fe8cde6f4b7f6eef225a Mon Sep 17 00:00:00 2001
From: Patrick Devine <pdevine@sonic.net>
Date: Wed, 14 Feb 2024 21:28:35 -0800
Subject: [PATCH] handle race condition while setting raw mode in windows
 (#2509)

---
 readline/readline.go         | 36 ++++++++++++++++++++++++++++--------
 readline/readline_unix.go    |  5 +++--
 readline/readline_windows.go |  2 +-
 readline/term.go             |  5 +++--
 readline/term_windows.go     |  5 +++--
 5 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/readline/readline.go b/readline/readline.go
index 202d9fa7..8ba7d89c 100644
--- a/readline/readline.go
+++ b/readline/readline.go
@@ -32,6 +32,8 @@ func (p *Prompt) placeholder() string {
 
 type Terminal struct {
 	outchan chan rune
+	rawmode bool
+	termios any
 }
 
 type Instance struct {
@@ -60,6 +62,16 @@ func New(prompt Prompt) (*Instance, error) {
 }
 
 func (i *Instance) Readline() (string, error) {
+	if !i.Terminal.rawmode {
+		fd := int(syscall.Stdin)
+		termios, err := SetRawMode(fd)
+		if err != nil {
+			return "", err
+		}
+		i.Terminal.rawmode = true
+		i.Terminal.termios = termios
+	}
+
 	prompt := i.Prompt.prompt()
 	if i.Pasting {
 		// force alt prompt when pasting
@@ -67,13 +79,12 @@ func (i *Instance) Readline() (string, error) {
 	}
 	fmt.Print(prompt)
 
-	fd := int(syscall.Stdin)
-	termios, err := SetRawMode(fd)
-	if err != nil {
-		return "", err
-	}
-	// nolint: errcheck
-	defer UnsetRawMode(fd, termios)
+	defer func() {
+		fd := int(syscall.Stdin)
+		// nolint: errcheck
+		UnsetRawMode(fd, i.Terminal.termios)
+		i.Terminal.rawmode = false
+	}()
 
 	buf, _ := NewBuffer(i.Prompt)
 
@@ -205,7 +216,8 @@ func (i *Instance) Readline() (string, error) {
 		case CharCtrlW:
 			buf.DeleteWord()
 		case CharCtrlZ:
-			return handleCharCtrlZ(fd, termios)
+			fd := int(syscall.Stdin)
+			return handleCharCtrlZ(fd, i.Terminal.termios)
 		case CharEnter:
 			output := buf.String()
 			if output != "" {
@@ -236,8 +248,16 @@ func (i *Instance) HistoryDisable() {
 }
 
 func NewTerminal() (*Terminal, error) {
+	fd := int(syscall.Stdin)
+	termios, err := SetRawMode(fd)
+	if err != nil {
+		return nil, err
+	}
+
 	t := &Terminal{
 		outchan: make(chan rune),
+		rawmode: true,
+		termios: termios,
 	}
 
 	go t.ioloop()
diff --git a/readline/readline_unix.go b/readline/readline_unix.go
index 73930c3d..76cff8c8 100644
--- a/readline/readline_unix.go
+++ b/readline/readline_unix.go
@@ -6,8 +6,9 @@ import (
 	"syscall"
 )
 
-func handleCharCtrlZ(fd int, termios *Termios) (string, error) {
-	if err := UnsetRawMode(fd, termios); err != nil {
+func handleCharCtrlZ(fd int, termios any) (string, error) {
+	t := termios.(*Termios)
+	if err := UnsetRawMode(fd, t); err != nil {
 		return "", err
 	}
 
diff --git a/readline/readline_windows.go b/readline/readline_windows.go
index c8178903..b4e96b25 100644
--- a/readline/readline_windows.go
+++ b/readline/readline_windows.go
@@ -1,6 +1,6 @@
 package readline
 
-func handleCharCtrlZ(fd int, state *State) (string, error) {
+func handleCharCtrlZ(fd int, state any) (string, error) {
 	// not supported
 	return "", nil
 }
diff --git a/readline/term.go b/readline/term.go
index 45757e6a..9d747162 100644
--- a/readline/term.go
+++ b/readline/term.go
@@ -25,8 +25,9 @@ func SetRawMode(fd int) (*Termios, error) {
 	return termios, setTermios(fd, &newTermios)
 }
 
-func UnsetRawMode(fd int, termios *Termios) error {
-	return setTermios(fd, termios)
+func UnsetRawMode(fd int, termios any) error {
+	t := termios.(*Termios)
+	return setTermios(fd, t)
 }
 
 // IsTerminal returns true if the given file descriptor is a terminal.
diff --git a/readline/term_windows.go b/readline/term_windows.go
index 3d1c80e1..a40fbaa3 100644
--- a/readline/term_windows.go
+++ b/readline/term_windows.go
@@ -56,7 +56,8 @@ func SetRawMode(fd int) (*State, error) {
 	return &State{st}, nil
 }
 
-func UnsetRawMode(fd int, state *State) error {
-	_, _, err := syscall.SyscallN(procSetConsoleMode.Addr(), uintptr(fd), uintptr(state.mode), 0)
+func UnsetRawMode(fd int, state any) error {
+	s := state.(*State)
+	_, _, err := syscall.SyscallN(procSetConsoleMode.Addr(), uintptr(fd), uintptr(s.mode), 0)
 	return err
 }