On Posix: Don't shutdown (half) the connection from the client.

This triggered POLLHUP too early on Mac.

platforms/posix/src/px4_daemon/client.cpp

@@ -124,12 +124,6 @@ Client::_send_cmds(const int argc, const char **argv)
 		buf += n_sent;
 	}
 
-	// Let the server know we're done writing.
-	if (shutdown(_fd, SHUT_WR) < 0) {
-		PX4_ERR("shutdown() failed: %s", strerror(errno));
-		return -1;
-	}
-
 	return 0;
 }
 

platforms/posix/src/px4_daemon/server.cpp

@@ -220,14 +220,15 @@ void
 		cmd.resize(n + 1024);
 		ssize_t n_read = read(fd, &cmd[n], cmd.size() - n);
 
-		if (n_read < 0) {
+		if (n_read <= 0) {
 			_cleanup(fd);
 			return nullptr;
 		}
 
 		cmd.resize(n + n_read);
 
-		if (n_read == 0) {
+		// Command ends in 0x00 (no tty) or 0x01 (tty).
+		if (!cmd.empty() && cmd.back() < 2) {
 			break;
 		}
 	}