Add support for Cgywin, apparently it is enough just to open the tty again in

the server and fd passing is not necessary. Needs some ifdefs unfortunately but
no way around that and some of them can go next time we're willing to do a
protocol bump. Patch from J Raynor jxraynor at gmail dot com.

client.c

@@ -328,8 +328,13 @@ client_send_identify(int flags)
 	    strlcpy(data.term, term, sizeof data.term) >= sizeof data.term)
 		*data.term = '\0';
 
+#ifdef __CYGWIN__
+	snprintf(&data.ttyname, sizeof data.ttyname, "%s",
+	    ttyname(STDIN_FILENO));
+#else
 	if ((fd = dup(STDIN_FILENO)) == -1)
 		fatal("dup failed");
+#endif
 	imsg_compose(&client_ibuf,
 	    MSG_IDENTIFY, PROTOCOL_VERSION, -1, fd, &data, sizeof data);
 	client_update_event();

compat.h

@@ -30,6 +30,10 @@
 #define __packed __attribute__ ((__packed__))
 #endif
 
+#ifndef ECHOPRT
+#define ECHOPRT 0
+#endif
+
 #ifndef HAVE_BSD_TYPES
 typedef uint8_t u_int8_t;
 typedef uint16_t u_int16_t;
@@ -210,6 +214,7 @@ int	 	 daemon(int, int);
 
 #ifndef HAVE_B64_NTOP
 /* b64_ntop.c */
+#undef b64_ntop /* for Cygwin */
 int		 b64_ntop(const char *, size_t, char *, size_t);
 #endif
 

server-client.c

@@ -825,9 +825,12 @@ server_client_msg_dispatch(struct client *c)
 		case MSG_IDENTIFY:
 			if (datalen != sizeof identifydata)
 				fatalx("bad MSG_IDENTIFY size");
+			memcpy(&identifydata, imsg.data, sizeof identifydata);
+#ifdef __CYGWIN__
+			imsg.fd = open(identifydata.ttyname, O_RDWR|O_NOCTTY);
+#endif
 			if (imsg.fd == -1)
 				fatalx("MSG_IDENTIFY missing fd");
-			memcpy(&identifydata, imsg.data, sizeof identifydata);
 
 			server_client_msg_identify(c, &identifydata, imsg.fd);
 			break;

tmux.h

@@ -471,6 +471,10 @@ struct msg_identify_data {
 
 	char		term[TERMINAL_LENGTH];
 
+#ifdef __CYGWIN__
+	char		ttyname[TTY_NAME_MAX];
+#endif
+
 #define IDENTIFY_UTF8 0x1
 #define IDENTIFY_256COLOURS 0x2
 /* 0x4 unused */