Use fdforkpty() instead of our own unwrapped versions.

Makefile

@@ -95,7 +95,6 @@ SRCS=	alerts.c \
 	paste.c \
 	proc.c \
 	procname.c \
-	pty.c \
 	resize.c \
 	screen-redraw.c \
 	screen-write.c \

pty.c

@@ -1,67 +0,0 @@
-/* $OpenBSD$ */
-
-/*
- * Copyright (c) 2017 Nicholas Marriott <nicholas.marriott@gmail.com>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
- * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
- * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-#include <sys/types.h>
-#include <sys/ioctl.h>
-#include <sys/time.h>
-#include <sys/tty.h>
-
-#include <fcntl.h>
-#include <string.h>
-#include <termios.h>
-#include <unistd.h>
-#include <util.h>
-
-int	pty_open(int *);
-pid_t	pty_fork(int, int *, char *, size_t, struct winsize *);
-
-int
-pty_open(int *fd)
-{
-	*fd = open(PATH_PTMDEV, O_RDWR|O_CLOEXEC);
-	if (*fd < 0)
-	    return (-1);
-	return (0);
-}
-
-pid_t
-pty_fork(int ptmfd, int *fd, char *name, size_t namelen, struct winsize *ws)
-{
-	struct ptmget	ptm;
-	pid_t		pid;
-
-	if (ioctl(ptmfd, PTMGET, &ptm) == -1)
-		return (-1);
-
-	strlcpy(name, ptm.sn, namelen);
-	ioctl(ptm.sfd, TIOCSWINSZ, ws);
-
-	switch (pid = fork()) {
-	case -1:
-		close(ptm.cfd);
-		close(ptm.sfd);
-		return (-1);
-	case 0:
-		close(ptm.cfd);
-		login_tty(ptm.sfd);
-		return (0);
-	}
-	*fd = ptm.cfd;
-	close(ptm.sfd);
-	return (pid);
-}

tmux.c

@@ -32,6 +32,7 @@
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
+#include <util.h>
 
 #include "tmux.h"
 
@@ -260,8 +261,8 @@ main(int argc, char **argv)
 	if (shellcmd != NULL && argc != 0)
 		usage();
 
-	if (pty_open(&ptm_fd) != 0)
-		errx(1, "open(\"/dev/ptm\"");
+	if ((ptm_fd = getptmfd()) == -1)
+		err(1, "getptmfd");
 	if (pledge("stdio rpath wpath cpath flock fattr unix getpw sendfd "
 	    "recvfd proc exec tty ps", NULL) != 0)
 		err(1, "pledge");

tmux.h

@@ -2307,8 +2307,4 @@ void		 style_apply_update(struct grid_cell *, struct options *,
 int		 style_equal(const struct grid_cell *,
 		     const struct grid_cell *);
 
-/* pty.c */
-int		 pty_open(int *);
-pid_t		 pty_fork(int, int *, char *, size_t, struct winsize *);
-
 #endif /* TMUX_H */

window.c

@@ -883,7 +883,7 @@ window_pane_spawn(struct window_pane *wp, int argc, char **argv,
 	ws.ws_col = screen_size_x(&wp->base);
 	ws.ws_row = screen_size_y(&wp->base);
 
-	wp->pid = pty_fork(ptm_fd, &wp->fd, wp->tty, sizeof wp->tty, &ws);
+	wp->pid = fdforkpty(ptm_fd, &wp->fd, wp->tty, NULL, &ws);
 	switch (wp->pid) {
 	case -1:
 		wp->fd = -1;