don't write openpty results until success is determined

not only is this semantically more correct; it also reduces code size
slightly by eliminating the need for the compiler to assume the
possibility of aliasing.

src/misc/openpty.c

@@ -6,28 +6,30 @@
 
 /* Nonstandard, but vastly superior to the standard functions */
 
-int openpty(int *m, int *s, char *name, const struct termios *tio, const struct winsize *ws)
+int openpty(int *pm, int *ps, char *name, const struct termios *tio, const struct winsize *ws)
 {
-	int n=0;
+	int m, s, n=0;
 	char buf[20];
 
-	*m = open("/dev/ptmx", O_RDWR|O_NOCTTY);
-	if (*m < 0) return -1;
+	m = open("/dev/ptmx", O_RDWR|O_NOCTTY);
+	if (m < 0) return -1;
 
-	if (ioctl(*m, TIOCSPTLCK, &n) || ioctl (*m, TIOCGPTN, &n)) {
-		close(*m);
+	if (ioctl(m, TIOCSPTLCK, &n) || ioctl (m, TIOCGPTN, &n)) {
+		close(m);
 		return -1;
 	}
 
 	if (!name) name = buf;
 	snprintf(name, sizeof buf, "/dev/pts/%d", n);
-	if ((*s = open(name, O_RDWR|O_NOCTTY)) < 0) {
-		close(*m);
+	if ((s = open(name, O_RDWR|O_NOCTTY)) < 0) {
+		close(m);
 		return -1;
 	}
 
-	if (tio) tcsetattr(*s, TCSANOW, tio);
-	if (ws) ioctl(*s, TIOCSWINSZ, ws);
+	if (tio) tcsetattr(s, TCSANOW, tio);
+	if (ws) ioctl(s, TIOCSWINSZ, ws);
 
+	*pm = m;
+	*ps = s;
 	return 0;
 }