Merge pull request #3325 from MichaelEischer/fix-mintty-output

Fix windows terminal output for mintty

internal/ui/termstatus/status.go

@@ -67,7 +67,7 @@ func New(wr io.Writer, errWriter io.Writer, disableStatus bool) *Terminal {
 		return t
 	}
 
-	if d, ok := wr.(fder); ok && canUpdateStatus(d.Fd()) {
+	if d, ok := wr.(fder); ok && CanUpdateStatus(d.Fd()) {
 		// only use the fancy status code when we're running on a real terminal.
 		t.canUpdateStatus = true
 		t.fd = d.Fd()

internal/ui/termstatus/terminal_unix.go

@@ -20,9 +20,9 @@ func moveCursorUp(wr io.Writer, fd uintptr) func(io.Writer, uintptr, int) {
 	return posixMoveCursorUp
 }
 
-// canUpdateStatus returns true if status lines can be printed, the process
+// CanUpdateStatus returns true if status lines can be printed, the process
 // output is not redirected to a file or pipe.
-func canUpdateStatus(fd uintptr) bool {
+func CanUpdateStatus(fd uintptr) bool {
 	if !terminal.IsTerminal(int(fd)) {
 		return false
 	}

internal/ui/termstatus/terminal_windows.go

@@ -4,6 +4,7 @@ package termstatus
 
 import (
 	"io"
+	"strings"
 	"syscall"
 	"unsafe"
 
@@ -80,19 +81,47 @@ func isPipe(fd uintptr) bool {
 	return err == nil && typ == windows.FILE_TYPE_PIPE
 }
 
-// canUpdateStatus returns true if status lines can be printed, the process
+func getFileNameByHandle(fd uintptr) (string, error) {
+	type FILE_NAME_INFO struct {
+		FileNameLength int32
+		FileName       [windows.MAX_LONG_PATH]uint16
+	}
+
+	var fi FILE_NAME_INFO
+	err := windows.GetFileInformationByHandleEx(windows.Handle(fd), windows.FileNameInfo, (*byte)(unsafe.Pointer(&fi)), uint32(unsafe.Sizeof(fi)))
+	if err != nil {
+		return "", err
+	}
+
+	filename := syscall.UTF16ToString(fi.FileName[:])
+	return filename, nil
+}
+
+// CanUpdateStatus returns true if status lines can be printed, the process
 // output is not redirected to a file or pipe.
-func canUpdateStatus(fd uintptr) bool {
+func CanUpdateStatus(fd uintptr) bool {
 	// easy case, the terminal is cmd or psh, without redirection
 	if isWindowsTerminal(fd) {
 		return true
 	}
 
-	// check that the output file type is a pipe (0x0003)
+	// pipes require special handling
 	if !isPipe(fd) {
 		return false
 	}
 
-	// assume we're running in mintty/cygwin
-	return true
+	fn, err := getFileNameByHandle(fd)
+	if err != nil {
+		return false
+	}
+
+	// inspired by https://github.com/RyanGlScott/mintty/blob/master/src/System/Console/MinTTY/Win32.hsc
+	// terminal: \msys-dd50a72ab4668b33-pty0-to-master
+	// pipe to cat: \msys-dd50a72ab4668b33-13244-pipe-0x16
+	if (strings.HasPrefix(fn, "\\cygwin-") || strings.HasPrefix(fn, "\\msys-")) &&
+		strings.Contains(fn, "-pty") && strings.HasSuffix(fn, "-master") {
+		return true
+	}
+
+	return false
 }

internal/ui/termstatus/terminal_windows_test.go

@@ -0,0 +1,30 @@
+package termstatus
+
+import (
+	"syscall"
+	"testing"
+
+	"golang.org/x/sys/windows"
+
+	rtest "github.com/restic/restic/internal/test"
+)
+
+func TestIsMinTTY(t *testing.T) {
+	for _, test := range []struct {
+		path   string
+		result bool
+	}{
+		{`\\.\pipe\msys-dd50a72ab4668b33-pty0-to-master`, true},
+		{`\\.\pipe\msys-dd50a72ab4668b33-13244-pipe-0x16`, false},
+	} {
+		filename, err := syscall.UTF16FromString(test.path)
+		rtest.OK(t, err)
+		handle, err := windows.CreateNamedPipe(&filename[0], windows.PIPE_ACCESS_DUPLEX,
+			windows.PIPE_TYPE_BYTE, 1, 1024, 1024, 0, nil)
+		rtest.OK(t, err)
+		defer windows.CloseHandle(handle)
+
+		rtest.Assert(t, CanUpdateStatus(uintptr(handle)) == test.result,
+			"expected CanUpdateStatus(%v) == %v", test.path, test.result)
+	}
+}