From 29730ad94e67db71085142e181063841a3373377 Mon Sep 17 00:00:00 2001
From: Tobias Kaupat <code@niondir.de>
Date: Fri, 28 Jul 2017 10:04:49 +0200
Subject: [PATCH] Add RTS and DTR to GetModemStatusBits for windows

---
 serial.go         |  2 ++
 serial_windows.go | 25 ++++++++++++++++---------
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/serial.go b/serial.go
index 46eb521..87857d3 100644
--- a/serial.go
+++ b/serial.go
@@ -51,6 +51,8 @@ type ModemStatusBits struct {
 	DSR bool // DataSetReady status
 	RI  bool // RingIndicator status
 	DCD bool // DataCarrierDetect status
+	RTS bool // ReadyToSend status (outgoing)
+	DTR bool // DataTerminalReady status (outgoing)
 }
 
 // Open opens the serial port using the specified modes
diff --git a/serial_windows.go b/serial_windows.go
index 4a504ef..8081619 100644
--- a/serial_windows.go
+++ b/serial_windows.go
@@ -144,7 +144,7 @@ const (
 	dcbInX                          = 0x00000200
 	dcbErrorChar                    = 0x00000400
 	dcbNull                         = 0x00000800
-	dcbRTSControlDisbaleMask        = ^uint32(0x00003000)
+	dcbRTSControlDisableMask        = ^uint32(0x00003000)
 	dcbRTSControlEnable             = 0x00001000
 	dcbRTSControlHandshake          = 0x00002000
 	dcbRTSControlToggle             = 0x00003000
@@ -303,7 +303,7 @@ func (port *windowsPort) SetRTS(rts bool) error {
 	if err := getCommState(port.handle, params); err != nil {
 		return &PortError{causedBy: err}
 	}
-	params.Flags &= dcbRTSControlDisbaleMask
+	params.Flags &= dcbRTSControlDisableMask
 	if rts {
 		params.Flags |= dcbRTSControlEnable
 	}
@@ -314,15 +314,22 @@ func (port *windowsPort) SetRTS(rts bool) error {
 }
 
 func (port *windowsPort) GetModemStatusBits() (*ModemStatusBits, error) {
-	var bits uint32
-	if !getCommModemStatus(port.handle, &bits) {
+	var modemStatus uint32
+	if !getCommModemStatus(port.handle, &modemStatus) {
 		return nil, &PortError{}
 	}
+	var commState dcb
+	if err := getCommState(port.handle, &commState); err != nil {
+		return nil, &PortError{causedBy: err}
+	}
+
 	return &ModemStatusBits{
-		CTS: (bits & msCTSOn) != 0,
-		DCD: (bits & msRLSDOn) != 0,
-		DSR: (bits & msDSROn) != 0,
-		RI:  (bits & msRingOn) != 0,
+		CTS: (modemStatus & msCTSOn) != 0,
+		DCD: (modemStatus & msRLSDOn) != 0,
+		DSR: (modemStatus & msDSROn) != 0,
+		RI:  (modemStatus & msRingOn) != 0,
+		RTS: (commState.Flags & dcbRTSControlEnable) != 0,
+		DTR: (commState.Flags & dcbDTRControlEnable) != 0,
 	}, nil
 }
 
@@ -369,7 +376,7 @@ func nativeOpen(portName string, mode *Mode) (*windowsPort, error) {
 		port.Close()
 		return nil, &PortError{code: InvalidSerialPort}
 	}
-	params.Flags &= dcbRTSControlDisbaleMask
+	params.Flags &= dcbRTSControlDisableMask
 	params.Flags |= dcbRTSControlEnable
 	params.Flags &= dcbDTRControlDisableMask
 	params.Flags |= dcbDTRControlEnable