Fix problems with window sizing seen by Raghavendra D Prabhu when

starting tmux from .xinitrc.

One of the very few things the server relies on the client for now is to
pass through a message on SIGWINCH, but there is a condition where
potentially a SIGWINCH may be lost during the transition from unattached
(main.c) to attached (client.c). So trigger a size change immediately
after the client installs its SIGWINCH handler.

Also, when the terminal is resized, reset the scroll region and cursor
position. Previously, we were clearing our saved idea of these, but in
fact some terminals do not reset them on resize, so this caused problems
during redraw.

While here make a resize to the same size not cause a redraw and rename
the tmux.out output log file to include the tmux PID.

4 files changed, 41 insertions, 12 deletions

diff --git a/client.c b/client.c
index 326ca100..35cf2801 100644
--- a/client.c
+++ b/client.c
@@ -176,6 +176,13 @@ client_main(void)
 	set_signals(client_signal);
 
 	/*
+	 * Send a resize message immediately in case the terminal size has
+	 * changed between the identify message to the server and the MSG_READY
+	 * telling us to move into the client code.
+	 */
+	 client_write_server(MSG_RESIZE, NULL, 0);
+
+	/*
 	 * imsg_read in the first client poll loop (before the terminal has
 	 * been initialised) may have read messages into the buffer after the
 	 * MSG_READY switched to here. Process anything outstanding now to
diff --git a/server-client.c b/server-client.c
index 9d550386..301c986a 100644
--- a/server-client.c
+++ b/server-client.c
@@ -561,9 +561,10 @@ server_client_msg_dispatch(struct client *c)
 			if (datalen != 0)
 				fatalx("bad MSG_RESIZE size");
 
-			tty_resize(&c->tty);
-			recalculate_sizes();
-			server_redraw_client(c);
+			if (tty_resize(&c->tty)) {
+				recalculate_sizes();
+				server_redraw_client(c);
+			}
 			break;
 		case MSG_EXITING:
 			if (datalen != 0)
diff --git a/tmux.h b/tmux.h
index 3069f89b..a9e41351 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1351,7 +1351,7 @@ void	tty_puts(struct tty *, const char *);
 void	tty_putc(struct tty *, u_char);
 void	tty_pututf8(struct tty *, const struct grid_utf8 *);
 void	tty_init(struct tty *, int, char *);
-void	tty_resize(struct tty *);
+int	tty_resize(struct tty *);
 void	tty_start_tty(struct tty *);
 void	tty_stop_tty(struct tty *);
 void	tty_set_title(struct tty *, const char *);
diff --git a/tty.c b/tty.c
index 4fe946af..fa2cd552 100644
--- a/tty.c
+++ b/tty.c
@@ -73,34 +73,55 @@ tty_init(struct tty *tty, int fd, char *term)
 	tty->term_flags = 0;
 }
 
-void
+int
 tty_resize(struct tty *tty)
 {
 	struct winsize	ws;
+	u_int		sx, sy;
 
 	if (ioctl(tty->fd, TIOCGWINSZ, &ws) != -1) {
-		tty->sx = ws.ws_col;
-		tty->sy = ws.ws_row;
+		sx = ws.ws_col;
+		if (sx == 0)
+			sx = 80;
+		sy = ws.ws_row;
+		if (sy == 0)
+			sy = 24;
+	} else {
+		sx = 80;
+		sy = 24;
 	}
-	if (tty->sx == 0)
-		tty->sx = 80;
-	if (tty->sy == 0)
-		tty->sy = 24;
+	if (sx == tty->sx && sy == tty->sy)
+		return (0);
+	tty->sx = sx;
+	tty->sy = sy;
 
 	tty->cx = UINT_MAX;
 	tty->cy = UINT_MAX;
 
 	tty->rupper = UINT_MAX;
 	tty->rlower = UINT_MAX;
+
+	/*
+	 * If the terminal has been started, reset the actual scroll region and
+	 * cursor position, as this may not have happened.
+	 */
+	if (tty->flags & TTY_STARTED) {
+		tty_cursor(tty, 0, 0);
+		tty_region(tty, 0, tty->sy - 1);
+	}
+
+	return (1);
 }
 
 int
 tty_open(struct tty *tty, const char *overrides, char **cause)
 {
+	char	out[64];
 	int	fd;
 
 	if (debug_level > 3) {
-		fd = open("tmux.out", O_WRONLY|O_CREAT|O_TRUNC, 0644);
+		xsnprintf(out, sizeof out, "tmux-out-%ld.log", (long) getpid());
+		fd = open(out, O_WRONLY|O_CREAT|O_TRUNC, 0644);
 		if (fd != -1 && fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
 			fatal("fcntl failed");
 		tty->log_fd = fd;