Use MSYS=enable_pcon instead of winpty on mintty 3.4.5 or later

src/winpty_windows.go

@@ -6,8 +6,46 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+
+	"github.com/junegunn/fzf/src/util"
 )
 
+func isMintty345() bool {
+	return util.CompareVersions(os.Getenv("TERM_PROGRAM_VERSION"), "3.4.5") >= 0
+}
+
+func needWinpty(opts *Options) bool {
+	if os.Getenv("TERM_PROGRAM") != "mintty" {
+		return false
+	}
+	if isMintty345() {
+		/*
+		 See: https://github.com/junegunn/fzf/issues/3809
+
+		 "MSYS=enable_pcon" allows fzf to run properly on mintty 3.4.5 or later,
+		 however `--height` option still doesn't work, so let's just disable it.
+
+		 We're not going to worry too much about restoring the original value.
+		*/
+		if os.Getenv("MSYS") == "enable_pcon" {
+			opts.Height = heightSpec{}
+			return false
+		}
+
+		// Setting the environment variable here unfortunately doesn't help,
+		// so we need to start a child process with "MSYS=enable_pcon"
+		//   os.Setenv("MSYS", "enable_pcon")
+		return true
+	}
+	if _, err := exec.LookPath("winpty"); err != nil {
+		return false
+	}
+	if opts.NoWinpty {
+		return false
+	}
+	return true
+}
+
 func runWinpty(args []string, opts *Options) (int, error) {
 	sh, err := sh()
 	if err != nil {
@@ -20,6 +58,17 @@ func runWinpty(args []string, opts *Options) (int, error) {
 	}
 	argStr += ` --no-winpty --no-height`
 
+	if isMintty345() {
+		return runProxy(argStr, func(temp string) *exec.Cmd {
+			cmd := exec.Command(sh, temp)
+			cmd.Env = append(os.Environ(), "MSYS=enable_pcon")
+			cmd.Stdin = os.Stdin
+			cmd.Stdout = os.Stdout
+			cmd.Stderr = os.Stderr
+			return cmd
+		}, opts, false)
+	}
+
 	return runProxy(argStr, func(temp string) *exec.Cmd {
 		cmd := exec.Command(sh, "-c", fmt.Sprintf(`winpty < /dev/tty > /dev/tty -- sh %q`, temp))
 		cmd.Stdout = os.Stdout