diff --git a/cmd-set-buffer.c b/cmd-set-buffer.c
index 5b66dbee..eef2978e 100644
--- a/cmd-set-buffer.c
+++ b/cmd-set-buffer.c
@@ -57,14 +57,12 @@ cmd_set_buffer_exec(struct cmd *self, struct cmdq_item *item)
 {
 	struct args		*args = cmd_get_args(self);
 	struct client		*tc = cmdq_get_target_client(item);
-	struct paste_buffer	*pb;
-	char			*bufname, *bufdata = NULL, *cause = NULL;
+	struct paste_buffer	*pb = NULL;
+	char			*bufname = NULL, *bufdata = NULL, *cause = NULL;
 	const char		*olddata;
 	size_t			 bufsize = 0, newsize;
 
-	if (args_get(args, 'b') == NULL)
-		pb = NULL;
-	else {
+	if (args_get(args, 'b') != NULL) {
 		bufname = xstrdup(args_get(args, 'b'));
 		pb = paste_get_name(bufname);
 	}
diff --git a/control-notify.c b/control-notify.c
index 30f94194..ba6a8355 100644
--- a/control-notify.c
+++ b/control-notify.c
@@ -51,29 +51,24 @@ control_notify_window_layout_changed(struct window *w)
 	template = "%layout-change #{window_id} #{window_layout} "
 	    "#{window_visible_layout} #{window_raw_flags}";
 
+	/*
+	 * When the last pane in a window is closed it won't have a layout root
+	 * and we don't need to inform the client about the layout change
+	 * because the whole window will go away soon.
+	 */
+	wl = TAILQ_FIRST(&w->winlinks);
+	if (wl == NULL || w->layout_root == NULL)
+		return;
+	cp = format_single(NULL, template, NULL, NULL, wl, NULL);
+
 	TAILQ_FOREACH(c, &clients, entry) {
 		if (!CONTROL_SHOULD_NOTIFY_CLIENT(c) || c->session == NULL)
 			continue;
 		s = c->session;
-
-		if (winlink_find_by_window_id(&s->windows, w->id) == NULL)
-			continue;
-
-		/*
-		 * When the last pane in a window is closed it won't have a
-		 * layout root and we don't need to inform the client about the
-		 * layout change because the whole window will go away soon.
-		 */
-		if (w->layout_root == NULL)
-			continue;
-
-		wl = winlink_find_by_window(&s->windows, w);
-		if (wl != NULL) {
-			cp = format_single(NULL, template, c, NULL, wl, NULL);
+		if (winlink_find_by_window_id(&s->windows, w->id) != NULL)
 			control_write(c, "%s", cp);
-			free(cp);
-		}
 	}
+	free(cp);
 }
 
 void
diff --git a/control.c b/control.c
index c3bedde8..35f960d2 100644
--- a/control.c
+++ b/control.c
@@ -846,15 +846,13 @@ control_stop(struct client *c)
 
 /* Check session subscription. */
 static void
-control_check_subs_session(struct client *c, struct control_sub *csub)
+control_check_subs_session(struct client *c, struct control_sub *csub,
+    struct format_tree *ft)
 {
 	struct session		*s = c->session;
-	struct format_tree	*ft;
 	char			*value;
 
-	ft = format_create_defaults(NULL, c, s, NULL, NULL);
 	value = format_expand(ft, csub->format);
-	format_free(ft);
 
 	if (csub->last != NULL && strcmp(value, csub->last) == 0) {
 		free(value);
@@ -915,48 +913,38 @@ control_check_subs_pane(struct client *c, struct control_sub *csub)
 	}
 }
 
-/* Check all panes subscription. */
+/* Check all-panes subscription for a pane. */
 static void
-control_check_subs_all_panes(struct client *c, struct control_sub *csub)
+control_check_subs_all_panes_one(struct client *c, struct control_sub *csub,
+    struct format_tree *ft, struct winlink *wl, struct window_pane *wp)
 {
 	struct session		*s = c->session;
-	struct window_pane	*wp;
-	struct window		*w;
-	struct winlink		*wl;
-	struct format_tree	*ft;
+	struct window		*w = wl->window;
 	char			*value;
 	struct control_sub_pane	*csp, find;
 
-	RB_FOREACH(wl, winlinks, &s->windows) {
-		w = wl->window;
-		TAILQ_FOREACH(wp, &w->panes, entry) {
-			ft = format_create_defaults(NULL, c, s, wl, wp);
-			value = format_expand(ft, csub->format);
-			format_free(ft);
+	value = format_expand(ft, csub->format);
 
-			find.pane = wp->id;
-			find.idx = wl->idx;
+	find.pane = wp->id;
+	find.idx = wl->idx;
 
-			csp = RB_FIND(control_sub_panes, &csub->panes, &find);
-			if (csp == NULL) {
-				csp = xcalloc(1, sizeof *csp);
-				csp->pane = wp->id;
-				csp->idx = wl->idx;
-				RB_INSERT(control_sub_panes, &csub->panes, csp);
-			}
-
-			if (csp->last != NULL &&
-			    strcmp(value, csp->last) == 0) {
-				free(value);
-				continue;
-			}
-			control_write(c,
-			    "%%subscription-changed %s $%u @%u %u %%%u : %s",
-			    csub->name, s->id, w->id, wl->idx, wp->id, value);
-			free(csp->last);
-			csp->last = value;
-		}
+	csp = RB_FIND(control_sub_panes, &csub->panes, &find);
+	if (csp == NULL) {
+		csp = xcalloc(1, sizeof *csp);
+		csp->pane = wp->id;
+		csp->idx = wl->idx;
+		RB_INSERT(control_sub_panes, &csub->panes, csp);
 	}
+
+	if (csp->last != NULL && strcmp(value, csp->last) == 0) {
+		free(value);
+		return;
+	}
+	control_write(c,
+	    "%%subscription-changed %s $%u @%u %u %%%u : %s",
+	    csub->name, s->id, w->id, wl->idx, wp->id, value);
+	free(csp->last);
+	csp->last = value;
 }
 
 /* Check window subscription. */
@@ -1005,45 +993,38 @@ control_check_subs_window(struct client *c, struct control_sub *csub)
 	}
 }
 
-/* Check all windows subscription. */
+/* Check all-windows subscription for a window. */
 static void
-control_check_subs_all_windows(struct client *c, struct control_sub *csub)
+control_check_subs_all_windows_one(struct client *c, struct control_sub *csub,
+    struct format_tree *ft, struct winlink *wl)
 {
 	struct session			*s = c->session;
-	struct window			*w;
-	struct winlink			*wl;
-	struct format_tree		*ft;
+	struct window			*w = wl->window;
 	char				*value;
 	struct control_sub_window	*csw, find;
 
-	RB_FOREACH(wl, winlinks, &s->windows) {
-		w = wl->window;
+	value = format_expand(ft, csub->format);
 
-		ft = format_create_defaults(NULL, c, s, wl, NULL);
-		value = format_expand(ft, csub->format);
-		format_free(ft);
+	find.window = w->id;
+	find.idx = wl->idx;
 
-		find.window = w->id;
-		find.idx = wl->idx;
-
-		csw = RB_FIND(control_sub_windows, &csub->windows, &find);
-		if (csw == NULL) {
-			csw = xcalloc(1, sizeof *csw);
-			csw->window = w->id;
-			csw->idx = wl->idx;
-			RB_INSERT(control_sub_windows, &csub->windows, csw);
-		}
-
-		if (csw->last != NULL && strcmp(value, csw->last) == 0) {
-			free(value);
-			continue;
-		}
-		control_write(c,
-		    "%%subscription-changed %s $%u @%u %u - : %s",
-		    csub->name, s->id, w->id, wl->idx, value);
-		free(csw->last);
-		csw->last = value;
+	csw = RB_FIND(control_sub_windows, &csub->windows, &find);
+	if (csw == NULL) {
+		csw = xcalloc(1, sizeof *csw);
+		csw->window = w->id;
+		csw->idx = wl->idx;
+		RB_INSERT(control_sub_windows, &csub->windows, csw);
 	}
+
+	if (csw->last != NULL && strcmp(value, csw->last) == 0) {
+		free(value);
+		return;
+	}
+	control_write(c,
+	    "%%subscription-changed %s $%u @%u %u - : %s",
+	    csub->name, s->id, w->id, wl->idx, value);
+	free(csw->last);
+	csw->last = value;
 }
 
 /* Check subscriptions timer. */
@@ -1053,30 +1034,91 @@ control_check_subs_timer(__unused int fd, __unused short events, void *data)
 	struct client		*c = data;
 	struct control_state	*cs = c->control_state;
 	struct control_sub	*csub, *csub1;
+	struct session		*s = c->session;
+	struct format_tree	*ft;
+	struct winlink		*wl;
+	struct window_pane	*wp;
 	struct timeval		 tv = { .tv_sec = 1 };
+	int			 have_session = 0, have_all_panes = 0;
+	int			 have_all_windows = 0;
 
 	log_debug("%s: timer fired", __func__);
 	evtimer_add(&cs->subs_timer, &tv);
 
-	RB_FOREACH_SAFE(csub, control_subs, &cs->subs, csub1) {
+	/* Find which subscription types are present. */
+	RB_FOREACH(csub, control_subs, &cs->subs) {
 		switch (csub->type) {
 		case CONTROL_SUB_SESSION:
-			control_check_subs_session(c, csub);
-			break;
-		case CONTROL_SUB_PANE:
-			control_check_subs_pane(c, csub);
+			have_session = 1;
 			break;
 		case CONTROL_SUB_ALL_PANES:
-			control_check_subs_all_panes(c, csub);
+			have_all_panes = 1;
+			break;
+		case CONTROL_SUB_ALL_WINDOWS:
+			have_all_windows = 1;
+			break;
+		default:
+			break;
+		}
+	}
+
+	/* Check session subscriptions. */
+	if (have_session) {
+		ft = format_create_defaults(NULL, c, s, NULL, NULL);
+		RB_FOREACH_SAFE(csub, control_subs, &cs->subs, csub1) {
+			if (csub->type == CONTROL_SUB_SESSION)
+				control_check_subs_session(c, csub, ft);
+		}
+		format_free(ft);
+	}
+
+	/* Check pane and window subscriptions. */
+	RB_FOREACH_SAFE(csub, control_subs, &cs->subs, csub1) {
+		switch (csub->type) {
+		case CONTROL_SUB_PANE:
+			control_check_subs_pane(c, csub);
 			break;
 		case CONTROL_SUB_WINDOW:
 			control_check_subs_window(c, csub);
 			break;
+		case CONTROL_SUB_SESSION:
+		case CONTROL_SUB_ALL_PANES:
 		case CONTROL_SUB_ALL_WINDOWS:
-			control_check_subs_all_windows(c, csub);
 			break;
 		}
 	}
+
+	/* Check all-panes subscriptions. */
+	if (have_all_panes) {
+		RB_FOREACH(wl, winlinks, &s->windows) {
+			TAILQ_FOREACH(wp, &wl->window->panes, entry) {
+				ft = format_create_defaults(NULL, c, s, wl, wp);
+				RB_FOREACH_SAFE(csub, control_subs, &cs->subs,
+				    csub1) {
+					if (csub->type != CONTROL_SUB_ALL_PANES)
+						continue;
+					control_check_subs_all_panes_one(c,
+					    csub, ft, wl, wp);
+				}
+				format_free(ft);
+			}
+		}
+	}
+
+	/* Check all-windows subscriptions. */
+	if (have_all_windows) {
+		RB_FOREACH(wl, winlinks, &s->windows) {
+			ft = format_create_defaults(NULL, c, s, wl, NULL);
+			RB_FOREACH_SAFE(csub, control_subs, &cs->subs,
+			    csub1) {
+				if (csub->type != CONTROL_SUB_ALL_WINDOWS)
+					continue;
+				control_check_subs_all_windows_one(c, csub, ft,
+				    wl);
+			}
+			format_free(ft);
+		}
+	}
 }
 
 /* Add a subscription. */
diff --git a/grid.c b/grid.c
index c783f7b7..28a15d77 100644
--- a/grid.c
+++ b/grid.c
@@ -205,11 +205,17 @@ grid_clear_cell(struct grid *gd, u_int px, u_int py, u_int bg)
 	struct grid_line	*gl = &gd->linedata[py];
 	struct grid_cell_entry	*gce = &gl->celldata[px];
 	struct grid_extd_entry	*gee;
+	u_int			 old_offset = gce->offset;
+	int			 had_extd = (gce->flags & GRID_FLAG_EXTENDED);
 
 	memcpy(gce, &grid_cleared_entry, sizeof *gce);
 	if (bg != 8) {
 		if (bg & COLOUR_FLAG_RGB) {
-			grid_get_extended_cell(gl, gce, gce->flags);
+			if (had_extd && old_offset < gl->extdsize) {
+				gce->flags |= GRID_FLAG_EXTENDED;
+				gce->offset = old_offset;
+			} else
+				grid_get_extended_cell(gl, gce, gce->flags);
 			gee = grid_extended_cell(gl, gce, &grid_cleared_cell);
 			gee->bg = bg;
 		} else {
@@ -1089,12 +1095,16 @@ grid_string_cells(struct grid *gd, u_int px, u_int py, u_int nx,
 	off = 0;
 
 	gl = grid_peek_line(gd, py);
+	if (gl == NULL) {
+		buf[0] = '\0';
+		return (buf);
+	}
 	if (flags & GRID_STRING_EMPTY_CELLS)
 		end = gl->cellsize;
 	else
 		end = gl->cellused;
 	for (xx = px; xx < px + nx; xx++) {
-		if (gl == NULL || xx >= end)
+		if (xx >= end)
 			break;
 		grid_get_cell(gd, xx, py, &gc);
 		if (gc.flags & GRID_FLAG_PADDING)
diff --git a/window-copy.c b/window-copy.c
index f3a8507d..c4f10b37 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -355,7 +355,7 @@ window_copy_clone_screen(struct screen *src, struct screen *hint, u_int *cx,
 	if (trim) {
 		while (sy > screen_hsize(src)) {
 			gl = grid_peek_line(src->grid, sy - 1);
-			if (gl->cellused != 0)
+			if (gl == NULL || gl->cellused != 0)
 				break;
 			sy--;
 		}
@@ -3625,6 +3625,10 @@ window_copy_stringify(struct grid *gd, u_int py, u_int first, u_int last,
 	buf = xrealloc(buf, bufsize);
 
 	gl = grid_peek_line(gd, py);
+	if (gl == NULL) {
+		buf[*size - 1] = '\0';
+		return (buf);
+	}
 	bx = *size - 1;
 	for (ax = first; ax < last; ax++) {
 		d = window_copy_cellstring(gl, ax, &dlen, &allocated);
@@ -3670,6 +3674,10 @@ window_copy_cstrtocellpos(struct grid *gd, u_int ncells, u_int *ppx, u_int *ppy,
 	px = *ppx;
 	pywrap = *ppy;
 	gl = grid_peek_line(gd, pywrap);
+	if (gl == NULL) {
+		free(cells);
+		return;
+	}
 	while (cell < ncells) {
 		cells[cell].d = window_copy_cellstring(gl, px,
 		    &cells[cell].dlen, &cells[cell].allocated);
@@ -3679,6 +3687,8 @@ window_copy_cstrtocellpos(struct grid *gd, u_int ncells, u_int *ppx, u_int *ppy,
 			px = 0;
 			pywrap++;
 			gl = grid_peek_line(gd, pywrap);
+			if (gl == NULL)
+				break;
 		}
 	}
 
@@ -4080,7 +4090,7 @@ window_copy_visible_lines(struct window_copy_mode_data *data, u_int *start,
 
 	for (*start = gd->hsize - data->oy; *start > 0; (*start)--) {
 		gl = grid_peek_line(gd, (*start) - 1);
-		if (~gl->flags & GRID_LINE_WRAPPED)
+		if (gl == NULL || ~gl->flags & GRID_LINE_WRAPPED)
 			break;
 	}
 	*end = gd->hsize - data->oy + gd->sy;