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

5 files changed, 118 insertions, 5 deletions

diff --git a/src/core.go b/src/core.go
index f0728f80..ec25d1d0 100644
--- a/src/core.go
+++ b/src/core.go
@@ -3,7 +3,6 @@ package fzf
 
 import (
 	"os"
-	"os/exec"
 	"sync"
 	"time"
 
@@ -25,10 +24,8 @@ func Run(opts *Options) (int, error) {
 		return runTmux(os.Args, opts)
 	}
 
-	if os.Getenv("TERM_PROGRAM") == "mintty" && !opts.NoWinpty {
-		if _, err := exec.LookPath("winpty"); err == nil {
-			return runWinpty(os.Args, opts)
-		}
+	if needWinpty(opts) {
+		return runWinpty(os.Args, opts)
 	}
 
 	if err := postProcessOptions(opts); err != nil {
diff --git a/src/util/util.go b/src/util/util.go
index b5b27f28..9b926b8d 100644
--- a/src/util/util.go
+++ b/src/util/util.go
@@ -3,6 +3,7 @@ package util
 import (
 	"math"
 	"os"
+	"strconv"
 	"strings"
 	"time"
 
@@ -189,3 +190,34 @@ func ToKebabCase(s string) string {
 	}
 	return strings.ToLower(name)
 }
+
+// CompareVersions compares two version strings
+func CompareVersions(v1, v2 string) int {
+	parts1 := strings.Split(v1, ".")
+	parts2 := strings.Split(v2, ".")
+
+	atoi := func(s string) int {
+		n, e := strconv.Atoi(s)
+		if e != nil {
+			return 0
+		}
+		return n
+	}
+
+	for i := 0; i < Max(len(parts1), len(parts2)); i++ {
+		var p1, p2 int
+		if i < len(parts1) {
+			p1 = atoi(parts1[i])
+		}
+		if i < len(parts2) {
+			p2 = atoi(parts2[i])
+		}
+
+		if p1 > p2 {
+			return 1
+		} else if p1 < p2 {
+			return -1
+		}
+	}
+	return 0
+}
diff --git a/src/util/util_test.go b/src/util/util_test.go
index af0762b5..013f3c23 100644
--- a/src/util/util_test.go
+++ b/src/util/util_test.go
@@ -203,3 +203,34 @@ func TestStringWidth(t *testing.T) {
 		t.Errorf("Expected: %d, Actual: %d", 1, w)
 	}
 }
+
+func TestCompareVersions(t *testing.T) {
+	assert := func(a, b string, expected int) {
+		if result := CompareVersions(a, b); result != expected {
+			t.Errorf("Expected: %d, Actual: %d", expected, result)
+		}
+	}
+
+	assert("2", "1", 1)
+	assert("2", "2", 0)
+	assert("2", "10", -1)
+
+	assert("2.1", "2.2", -1)
+	assert("2.1", "2.1.1", -1)
+
+	assert("1.2.3", "1.2.2", 1)
+	assert("1.2.3", "1.2.3", 0)
+	assert("1.2.3", "1.2.3.0", 0)
+	assert("1.2.3", "1.2.4", -1)
+
+	// Different number of parts
+	assert("1.0.0", "1", 0)
+	assert("1.0.0", "1.0", 0)
+	assert("1.0.0", "1.0.0", 0)
+	assert("1.0", "1.0.0", 0)
+	assert("1", "1.0.0", 0)
+	assert("1.0.0", "1.0.0.1", -1)
+	assert("1.0.0.1.0", "1.0.0.1", 0)
+
+	assert("", "3.4.5", -1)
+}
diff --git a/src/winpty.go b/src/winpty.go
index 46f9400f..adee3b0b 100644
--- a/src/winpty.go
+++ b/src/winpty.go
@@ -4,6 +4,10 @@ package fzf
 
 import "errors"
 
+func needWinpty(_ *Options) bool {
+	return false
+}
+
 func runWinpty(_ []string, _ *Options) (int, error) {
 	return ExitError, errors.New("Not supported")
 }
diff --git a/src/winpty_windows.go b/src/winpty_windows.go
index 83802a2b..6d7e366f 100644
--- a/src/winpty_windows.go
+++ b/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