diff --git a/cmd-if-shell.c b/cmd-if-shell.c
index da0220ca..15432919 100644
--- a/cmd-if-shell.c
+++ b/cmd-if-shell.c
@@ -37,8 +37,8 @@ void	cmd_if_shell_free(void *);
 
 const struct cmd_entry cmd_if_shell_entry = {
 	"if-shell", "if",
-	"bt:", 2, 3,
-	"[-b] " CMD_TARGET_PANE_USAGE " shell-command command [command]",
+	"bFt:", 2, 3,
+	"[-bF] " CMD_TARGET_PANE_USAGE " shell-command command [command]",
 	0,
 	cmd_if_shell_exec
 };
@@ -56,7 +56,8 @@ cmd_if_shell_exec(struct cmd *self, struct cmd_q *cmdq)
 {
 	struct args			*args = self->args;
 	struct cmd_if_shell_data	*cdata;
-	char				*shellcmd;
+	char				*shellcmd, *cmd, *cause;
+	struct cmd_list			*cmdlist;
 	struct client			*c;
 	struct session			*s = NULL;
 	struct winlink			*wl = NULL;
@@ -84,6 +85,26 @@ cmd_if_shell_exec(struct cmd *self, struct cmd_q *cmdq)
 	shellcmd = format_expand(ft, args->argv[0]);
 	format_free(ft);
 
+	if (args_has(args, 'F')) {
+		cmd = NULL;
+		if (*shellcmd != '0' && *shellcmd != '\0')
+			cmd = args->argv[1];
+		else if (args->argc == 3)
+			cmd = args->argv[2];
+		if (cmd == NULL)
+			return (CMD_RETURN_NORMAL);
+		if (cmd_string_parse(cmd, &cmdlist, NULL, 0, &cause) != 0) {
+			if (cause != NULL) {
+				cmdq_error(cmdq, "%s", cause);
+				free(cause);
+			}
+			return (CMD_RETURN_ERROR);
+		}
+		cmdq_run(cmdq, cmdlist);
+		cmd_list_free(cmdlist);
+		return (CMD_RETURN_NORMAL);
+	}
+
 	cdata = xmalloc(sizeof *cdata);
 	cdata->cmd_if = xstrdup(args->argv[1]);
 	if (args->argc == 3)
diff --git a/cmd-split-window.c b/cmd-split-window.c
index f88b2f65..6b901254 100644
--- a/cmd-split-window.c
+++ b/cmd-split-window.c
@@ -36,8 +36,8 @@ enum cmd_retval	 cmd_split_window_exec(struct cmd *, struct cmd_q *);
 
 const struct cmd_entry cmd_split_window_entry = {
 	"split-window", "splitw",
-	"c:dF:l:hp:Pt:v", 0, -1,
-	"[-dhvP] [-c start-directory] [-F format] [-p percentage|-l size] "
+	"bc:dF:l:hp:Pt:v", 0, -1,
+	"[-bdhvP] [-c start-directory] [-F format] [-p percentage|-l size] "
 	CMD_TARGET_PANE_USAGE " [command]",
 	0,
 	cmd_split_window_exec
@@ -144,7 +144,8 @@ cmd_split_window_exec(struct cmd *self, struct cmd_q *cmdq)
 	if (*shell == '\0' || areshell(shell))
 		shell = _PATH_BSHELL;
 
-	if ((lc = layout_split_pane(wp, type, size, 0)) == NULL) {
+	lc = layout_split_pane(wp, type, size, args_has(args, 'b'));
+	if (lc == NULL) {
 		cause = xstrdup("pane too small");
 		goto error;
 	}
diff --git a/format.c b/format.c
index e7fd3e1f..fff9a695 100644
--- a/format.c
+++ b/format.c
@@ -40,8 +40,26 @@ int	 format_replace(struct format_tree *, const char *, size_t, char **,
 char	*format_get_command(struct window_pane *);
 void	 format_window_pane_tabs(struct format_tree *, struct window_pane *);
 
+/* Entry in format tree. */
+struct format_entry {
+	char		       *key;
+	char		       *value;
+
+	RB_ENTRY(format_entry)	entry;
+};
+
+/* Tree of format entries. */
+struct format_tree {
+	struct window	*w;
+	struct session	*s;
+
+	RB_HEAD(format_rb_tree, format_entry) tree;
+};
+
 /* Format key-value replacement entry. */
-RB_GENERATE(format_tree, format_entry, entry, format_cmp);
+int	format_cmp(struct format_entry *, struct format_entry *);
+RB_PROTOTYPE(format_rb_tree, format_entry, entry, format_cmp);
+RB_GENERATE(format_rb_tree, format_entry, entry, format_cmp);
 
 /* Format tree comparison function. */
 int
@@ -117,8 +135,8 @@ format_create(void)
 	struct format_tree	*ft;
 	char			 host[MAXHOSTNAMELEN], *ptr;
 
-	ft = xmalloc(sizeof *ft);
-	RB_INIT(ft);
+	ft = xcalloc(1, sizeof *ft);
+	RB_INIT(&ft->tree);
 
 	if (gethostname(host, sizeof host) == 0) {
 		format_add(ft, "host", "%s", host);
@@ -134,14 +152,10 @@ format_create(void)
 void
 format_free(struct format_tree *ft)
 {
-	struct format_entry	*fe, *fe_next;
+	struct format_entry	*fe, *fe1;
 
-	fe_next = RB_MIN(format_tree, ft);
-	while (fe_next != NULL) {
-		fe = fe_next;
-		fe_next = RB_NEXT(format_tree, ft, fe);
-
-		RB_REMOVE(format_tree, ft, fe);
+	RB_FOREACH_SAFE(fe, format_rb_tree, &ft->tree, fe1) {
+		RB_REMOVE(format_rb_tree, &ft->tree, fe);
 		free(fe->value);
 		free(fe->key);
 		free(fe);
@@ -165,7 +179,7 @@ format_add(struct format_tree *ft, const char *key, const char *fmt, ...)
 	xvasprintf(&fe->value, fmt, ap);
 	va_end(ap);
 
-	fe_now = RB_INSERT(format_tree, ft, fe);
+	fe_now = RB_INSERT(format_rb_tree, &ft->tree, fe);
 	if (fe_now != NULL) {
 		free(fe_now->value);
 		fe_now->value = fe->value;
@@ -179,9 +193,32 @@ const char *
 format_find(struct format_tree *ft, const char *key)
 {
 	struct format_entry	*fe, fe_find;
+	struct options_entry	*o;
+	static char		 s[16];
+
+	o = options_find(&global_options, key);
+	if (o == NULL && ft->w != NULL)
+		o = options_find(&ft->w->options, key);
+	if (o == NULL)
+		o = options_find(&global_w_options, key);
+	if (o == NULL && ft->s != NULL)
+		o = options_find(&ft->s->options, key);
+	if (o == NULL)
+		o = options_find(&global_s_options, key);
+	if (o != NULL) {
+		switch (o->type) {
+		case OPTIONS_STRING:
+			return (o->str);
+		case OPTIONS_NUMBER:
+			snprintf(s, sizeof s, "%lld", o->num);
+			return (s);
+		case OPTIONS_STYLE:
+			return (style_tostring(&o->style));
+		}
+	}
 
 	fe_find.key = (char *) key;
-	fe = RB_FIND(format_tree, ft, &fe_find);
+	fe = RB_FIND(format_rb_tree, &ft->tree, &fe_find);
 	if (fe == NULL)
 		return (NULL);
 	return (fe->value);
@@ -206,7 +243,7 @@ format_replace(struct format_tree *ft, const char *key, size_t keylen,
 	copy[keylen] = '\0';
 
 	/* Is there a length limit or whatnot? */
-	if (!islower((u_char) *copy) && *copy != '?') {
+	if (!islower((u_char) *copy) && *copy != '@' && *copy != '?') {
 		while (*copy != ':' && *copy != '\0') {
 			switch (*copy) {
 			case '=':
@@ -389,6 +426,8 @@ format_session(struct format_tree *ft, struct session *s)
 	char			*tim;
 	time_t			 t;
 
+	ft->s = s;
+
 	format_add(ft, "session_name", "%s", s->name);
 	format_add(ft, "session_windows", "%u", winlink_count(&s->windows));
 	format_add(ft, "session_width", "%u", s->sx);
@@ -418,6 +457,9 @@ format_client(struct format_tree *ft, struct client *c)
 	time_t		 t;
 	struct session	*s;
 
+	if (ft->s == NULL)
+		ft->s = c->session;
+
 	format_add(ft, "client_height", "%u", c->tty.sy);
 	format_add(ft, "client_width", "%u", c->tty.sx);
 	if (c->tty.path != NULL)
@@ -463,6 +505,8 @@ format_window(struct format_tree *ft, struct window *w)
 {
 	char	*layout;
 
+	ft->w = w;
+
 	layout = layout_dump(w);
 
 	format_add(ft, "window_id", "@%u", w->id);
@@ -471,6 +515,8 @@ format_window(struct format_tree *ft, struct window *w)
 	format_add(ft, "window_height", "%u", w->sy);
 	format_add(ft, "window_layout", "%s", layout);
 	format_add(ft, "window_panes", "%u", window_count_panes(w));
+	format_add(ft, "window_zoomed_flag", "%u",
+	    !!(w->flags & WINDOW_ZOOMED));
 
 	free(layout);
 }
@@ -482,6 +528,9 @@ format_winlink(struct format_tree *ft, struct session *s, struct winlink *wl)
 	struct window	*w = wl->window;
 	char		*flags;
 
+	if (ft->w == NULL)
+		ft->w = wl->window;
+
 	flags = window_printable_flags(s, wl);
 
 	format_window(ft, w);
@@ -498,8 +547,6 @@ format_winlink(struct format_tree *ft, struct session *s, struct winlink *wl)
 	    !!(wl->flags & WINLINK_SILENCE));
 	format_add(ft, "window_last_flag", "%u",
 	    !!(wl == TAILQ_FIRST(&s->lastw)));
-	format_add(ft, "window_zoomed_flag", "%u",
-	    !!(wl->flags & WINDOW_ZOOMED));
 
 	free(flags);
 }
@@ -536,6 +583,9 @@ format_window_pane(struct format_tree *ft, struct window_pane *wp)
 	u_int			 i, idx;
 	char			*cmd, *cwd;
 
+	if (ft->w == NULL)
+		ft->w = wp->window;
+
 	size = 0;
 	for (i = 0; i < gd->hsize; i++) {
 		gl = &gd->linedata[i];
diff --git a/grid-view.c b/grid-view.c
index badabd56..078a0da4 100644
--- a/grid-view.c
+++ b/grid-view.c
@@ -184,7 +184,10 @@ grid_view_insert_cells(struct grid *gd, u_int px, u_int py, u_int nx)
 	px = grid_view_x(gd, px);
 	py = grid_view_y(gd, py);
 
-	sx = grid_view_x(gd, gd->sx);
+	if (gd->linedata[py].cellsize + nx < gd->sx)
+		sx = grid_view_x(gd, gd->linedata[py].cellsize + nx);
+	else
+		sx = grid_view_x(gd, gd->sx);
 
 	if (px == sx - 1)
 		grid_clear(gd, px, py, 1, 1);
@@ -201,7 +204,9 @@ grid_view_delete_cells(struct grid *gd, u_int px, u_int py, u_int nx)
 	px = grid_view_x(gd, px);
 	py = grid_view_y(gd, py);
 
-	sx = grid_view_x(gd, gd->sx);
+	sx = grid_view_x(gd, gd->linedata[py].cellsize);
+	if (sx < px + nx)
+		sx = px + nx;
 
 	grid_move_cells(gd, px, px + nx, py, sx - px - nx);
 	grid_clear(gd, sx - nx, py, px + nx - (sx - nx), 1);
diff --git a/log.c b/log.c
index 250a1da2..066165e8 100644
--- a/log.c
+++ b/log.c
@@ -46,7 +46,7 @@ log_open(const char *path)
 	if (log_file == NULL)
 		return;
 
-	setlinebuf(log_file);
+	setvbuf(log_file, NULL, _IOLBF, 0);
 	event_set_log_callback(log_event_cb);
 
 	tzset();
diff --git a/resize.c b/resize.c
index 73a728fa..9ad73c81 100644
--- a/resize.c
+++ b/resize.c
@@ -50,7 +50,7 @@ recalculate_sizes(void)
 	struct window		*w;
 	struct window_pane	*wp;
 	u_int			 i, j, ssx, ssy, has, limit;
-	int			 flag, has_status, is_zoomed;
+	int			 flag, has_status, is_zoomed, forced;
 
 	RB_FOREACH(s, sessions, &sessions) {
 		has_status = options_get_number(&s->options, "status");
@@ -116,18 +116,26 @@ recalculate_sizes(void)
 		if (ssx == UINT_MAX || ssy == UINT_MAX)
 			continue;
 
+		forced = 0;
 		limit = options_get_number(&w->options, "force-width");
-		if (limit >= PANE_MINIMUM && ssx > limit)
+		if (limit >= PANE_MINIMUM && ssx > limit) {
 			ssx = limit;
+			forced |= WINDOW_FORCEWIDTH;
+		}
 		limit = options_get_number(&w->options, "force-height");
-		if (limit >= PANE_MINIMUM && ssy > limit)
+		if (limit >= PANE_MINIMUM && ssy > limit) {
 			ssy = limit;
+			forced |= WINDOW_FORCEHEIGHT;
+		}
 
 		if (w->sx == ssx && w->sy == ssy)
 			continue;
 		log_debug("window size %u,%u (was %u,%u)", ssx, ssy, w->sx,
 		    w->sy);
 
+		w->flags &= ~(WINDOW_FORCEWIDTH|WINDOW_FORCEHEIGHT);
+		w->flags |= forced;
+
 		is_zoomed = w->flags & WINDOW_ZOOMED;
 		if (is_zoomed)
 			window_unzoom(w);
diff --git a/screen-redraw.c b/screen-redraw.c
index a7f713a5..ef9e539d 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -278,8 +278,37 @@ screen_redraw_draw_borders(struct client *c, int status, u_int top)
 	struct options		*oo = &c->session->options;
 	struct tty		*tty = &c->tty;
 	struct window_pane	*wp;
-	struct grid_cell	 active_gc, other_gc;
-	u_int		 	 i, j, type;
+	struct grid_cell	 active_gc, other_gc, msg_gc;
+	u_int		 	 i, j, type, msgx = 0, msgy = 0;
+	int			 small, flags;
+	char			 msg[256];
+	const char		*tmp;
+	size_t			 msglen = 0;
+
+	small = (tty->sy - status + top > w->sy) || (tty->sx > w->sx);
+	if (small) {
+		flags = w->flags & (WINDOW_FORCEWIDTH|WINDOW_FORCEHEIGHT);
+		if (flags == (WINDOW_FORCEWIDTH|WINDOW_FORCEHEIGHT))
+			tmp = "force-width, force-height";
+		else if (flags == WINDOW_FORCEWIDTH)
+			tmp = "force-width";
+		else if (flags == WINDOW_FORCEHEIGHT)
+			tmp = "force-height";
+		else
+			tmp = "a smaller client";
+		xsnprintf(msg, sizeof msg, "(size %ux%u from %s)",
+		    w->sx, w->sy, tmp);
+		msglen = strlen(msg);
+
+		if (tty->sy - 1 - status + top > w->sy && tty->sx >= msglen) {
+			msgx = tty->sx - msglen;
+			msgy = tty->sy - 1 - status + top;
+		} else if (tty->sx - w->sx > msglen) {
+			msgx = tty->sx - msglen;
+			msgy = tty->sy - 1 - status + top;
+		} else
+			small = 0;
+	}
 
 	style_apply(&other_gc, oo, "pane-border-style");
 	style_apply(&active_gc, oo, "pane-active-border-style");
@@ -290,6 +319,9 @@ screen_redraw_draw_borders(struct client *c, int status, u_int top)
 			type = screen_redraw_check_cell(c, i, j, &wp);
 			if (type == CELL_INSIDE)
 				continue;
+			if (type == CELL_OUTSIDE &&
+			    small && i > msgx && j == msgy)
+				continue;
 			if (screen_redraw_check_active(i, j, type, w, wp))
 				tty_attributes(tty, &active_gc);
 			else
@@ -298,6 +330,13 @@ screen_redraw_draw_borders(struct client *c, int status, u_int top)
 			tty_putc(tty, CELL_BORDERS[type]);
 		}
 	}
+
+	if (small) {
+		memcpy(&msg_gc, &grid_default_cell, sizeof msg_gc);
+		tty_attributes(tty, &msg_gc);
+		tty_cursor(tty, msgx, msgy);
+		tty_puts(tty, msg);
+	}
 }
 
 /* Draw the panes. */
diff --git a/tmux.1 b/tmux.1
index fb708ded..726f23a1 100644
--- a/tmux.1
+++ b/tmux.1
@@ -1761,7 +1761,7 @@ is given and the selected window is already the current window,
 the command behaves like
 .Ic last-window .
 .It Xo Ic split-window
-.Op Fl dhvP
+.Op Fl bdhvP
 .Op Fl c Ar start-directory
 .Oo Fl l
 .Ar size |
@@ -1785,6 +1785,10 @@ and
 .Fl p
 options specify the size of the new pane in lines (for vertical split) or in
 cells (for horizontal split), or as a percentage, respectively.
+The
+.Fl b
+option causes the new pane to be created to the left of or above
+.Ar target-pane .
 All other options have the same meaning as for the
 .Ic new-window
 command.
@@ -3039,12 +3043,17 @@ and
 .Ql } ,
 for example
 .Ql #{session_name} .
-Some variables also have an shorter alias such as
-.Ql #S .
+The possible variables are listed in the table below, or the name of a
+.Nm
+option may be used for an option's value.
+Some variables have a shorter alias such as
+.Ql #S ,
+and
 .Ql ##
 is replaced by a single
 .Ql # .
-Conditionals are also accepted by prefixing with
+.Pp
+Conditionals are available by prefixing with
 .Ql \&?
 and separating two alternatives with a comma;
 if the specified variable exists and is not zero, the first alternative
@@ -3055,7 +3064,15 @@ will include the string
 .Ql attached
 if the session is attached and the string
 .Ql not attached
-if it is unattached.
+if it is unattached, or
+.Ql #{?automatic-rename,yes,no}
+will include
+.Ql yes
+if
+.Ic automatic-rename
+is enabled, or
+.Ql no
+if not.
 A limit may be placed on the length of the resultant string by prefixing it
 by an
 .Ql = ,
@@ -3577,7 +3594,7 @@ Miscellaneous commands are as follows:
 .It Ic clock-mode Op Fl t Ar target-pane
 Display a large clock.
 .It Xo Ic if-shell
-.Op Fl b
+.Op Fl bF
 .Op Fl t Ar target-pane
 .Ar shell-command command
 .Op Ar command
@@ -3590,7 +3607,9 @@ if
 returns success or the second
 .Ar command
 otherwise.
-Before being executed, shell-command is expanded using the rules specified in the
+Before being executed,
+.Ar shell-command
+is expanded using the rules specified in the
 .Sx FORMATS
 section, including those relevant to
 .Ar target-pane .
@@ -3598,6 +3617,13 @@ With
 .Fl b ,
 .Ar shell-command
 is run in the background.
+.Pp
+If
+.Fl F
+is given,
+.Ar shell-command
+is not executed but considered success if neither empty nor zero (after formats
+are expanded).
 .It Ic lock-server
 .D1 (alias: Ic lock )
 Lock each client individually by running the command specified by the
diff --git a/tmux.h b/tmux.h
index 57077a65..61f2ca7c 100644
--- a/tmux.h
+++ b/tmux.h
@@ -944,7 +944,9 @@ struct window {
 #define WINDOW_ACTIVITY 0x2
 #define WINDOW_REDRAW 0x4
 #define WINDOW_SILENCE 0x8
-#define WINDOW_ZOOMED 0x10
+#define WINDOW_ZOOMED 0x1000
+#define WINDOW_FORCEWIDTH 0x2000
+#define WINDOW_FORCEHEIGHT 0x4000
 #define WINDOW_ALERTFLAGS (WINDOW_BELL|WINDOW_ACTIVITY|WINDOW_SILENCE)
 
 	struct options	 options;
@@ -1457,15 +1459,6 @@ struct options_table_entry {
 	const char	       *style;
 };
 
-/* Tree of format entries. */
-struct format_entry {
-	char		       *key;
-	char		       *value;
-
-	RB_ENTRY(format_entry)	entry;
-};
-RB_HEAD(format_tree, format_entry);
-
 /* Common command usages. */
 #define CMD_TARGET_PANE_USAGE "[-t target-pane]"
 #define CMD_TARGET_WINDOW_USAGE "[-t target-window]"
@@ -1509,8 +1502,7 @@ void		 cfg_print_causes(struct cmd_q *);
 void		 cfg_show_causes(struct session *);
 
 /* format.c */
-int		 format_cmp(struct format_entry *, struct format_entry *);
-RB_PROTOTYPE(format_tree, format_entry, entry, format_cmp);
+struct format_tree;
 struct format_tree *format_create(void);
 void		 format_free(struct format_tree *);
 void printflike(3, 4) format_add(struct format_tree *, const char *,
@@ -2232,9 +2224,6 @@ struct window_choose_data	*window_choose_add_window(struct window_pane *,
 struct window_choose_data	*window_choose_add_session(struct window_pane *,
 			struct client *, struct session *, const char *,
 			const char *, u_int);
-struct window_choose_data	*window_choose_add_item(struct window_pane *,
-			struct client *, struct winlink *, const char *,
-			const char *, u_int);
 void	window_choose_expand_all(struct window_pane *);
 void	window_choose_collapse_all(struct window_pane *);
 void	window_choose_set_current(struct window_pane *, u_int);
diff --git a/window-choose.c b/window-choose.c
index db092872..56016394 100644
--- a/window-choose.c
+++ b/window-choose.c
@@ -931,36 +931,6 @@ window_choose_add_session(struct window_pane *wp, struct client *c,
 	return (wcd);
 }
 
-struct window_choose_data *
-window_choose_add_item(struct window_pane *wp, struct client *c,
-    struct winlink *wl, const char *template, const char *action, u_int idx)
-{
-	struct window_choose_data	*wcd;
-	char				*expanded;
-
-	wcd = window_choose_data_create(TREE_OTHER, c, c->session);
-	wcd->idx = wl->idx;
-
-	wcd->ft_template = xstrdup(template);
-	format_add(wcd->ft, "line", "%u", idx);
-	format_session(wcd->ft, wcd->start_session);
-	format_winlink(wcd->ft, wcd->start_session, wl);
-	format_window_pane(wcd->ft, wl->window->active);
-
-	/*
-	 * Interpolate action here, since the data we pass back is the expanded
-	 * template itself.
-	 */
-	xasprintf(&expanded, "%s", format_expand(wcd->ft, wcd->ft_template));
-	wcd->command = cmd_template_replace(action, expanded, 1);
-	free(expanded);
-
-	window_choose_add(wp, wcd);
-
-	return (wcd);
-
-}
-
 struct window_choose_data *
 window_choose_add_window(struct window_pane *wp, struct client *c,
     struct session *s, struct winlink *wl, const char *template,