From 62ff5e4b010a9db695c79593d20ac92b0aed9558 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Sat, 18 Apr 2020 21:35:32 +0000
Subject: [PATCH] The PANE_REDRAW flag bit might be needed by other panes so we
 can't clear it on the first redraw, and it can't be set when we are finished
 or they would be redrawn again, so if the redraw is deferred for a client,
 copy the redraw flag into a separate set of bits just for that client.

---
 screen-redraw.c |  2 --
 server-client.c | 45 +++++++++++++++++++++++++++++++++++----------
 tmux.h          |  2 ++
 3 files changed, 37 insertions(+), 12 deletions(-)

diff --git a/screen-redraw.c b/screen-redraw.c
index 4c017706..c9e70590 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -474,7 +474,6 @@ screen_redraw_pane(struct client *c, struct window_pane *wp)
 	tty_sync_start(&c->tty);
 
 	screen_redraw_draw_pane(&ctx, wp);
-	wp->flags &= ~PANE_REDRAW;
 
 	tty_reset(&c->tty);
 	tty_sync_end(&c->tty);
@@ -564,7 +563,6 @@ screen_redraw_draw_panes(struct screen_redraw_ctx *ctx)
 	TAILQ_FOREACH(wp, &w->panes, entry) {
 		if (window_pane_visible(wp))
 			screen_redraw_draw_pane(ctx, wp);
-		wp->flags &= ~PANE_REDRAW;
 	}
 }
 
diff --git a/server-client.c b/server-client.c
index 14691fdc..6eda2b45 100644
--- a/server-client.c
+++ b/server-client.c
@@ -1370,6 +1370,7 @@ server_client_loop(void)
 				if (resize)
 					server_client_check_resize(wp);
 			}
+			wp->flags &= ~PANE_REDRAW;
 		}
 		check_window_name(w);
 	}
@@ -1679,8 +1680,11 @@ server_client_check_redraw(struct client *c)
 {
 	struct session		*s = c->session;
 	struct tty		*tty = &c->tty;
+	struct window		*w = c->session->curw->window;
 	struct window_pane	*wp;
 	int			 needed, flags, mode = tty->mode, new_flags = 0;
+	int			 redraw;
+	u_int			 bit = 0;
 	struct timeval		 tv = { .tv_usec = 1000 };
 	static struct event	 ev;
 	size_t			 left;
@@ -1705,7 +1709,7 @@ server_client_check_redraw(struct client *c)
 	if (c->flags & CLIENT_ALLREDRAWFLAGS)
 		needed = 1;
 	else {
-		TAILQ_FOREACH(wp, &c->session->curw->window->panes, entry) {
+		TAILQ_FOREACH(wp, &w->panes, entry) {
 			if (wp->flags & PANE_REDRAW) {
 				needed = 1;
 				break;
@@ -1722,25 +1726,46 @@ server_client_check_redraw(struct client *c)
 			log_debug("redraw timer started");
 			evtimer_add(&ev, &tv);
 		}
+		if (new_flags & CLIENT_REDRAWPANES) {
+			c->redraw_panes = 0;
+			TAILQ_FOREACH(wp, &w->panes, entry) {
+				if (wp->flags & PANE_REDRAW)
+					c->redraw_panes |= (1 << bit);
+				if (++bit == 64) {
+					/*
+					 * If more that 64 panes, give up and
+					 * just redraw the window.
+					 */
+					new_flags &= CLIENT_REDRAWPANES;
+					new_flags |= CLIENT_REDRAWWINDOW;
+					break;
+				}
+			}
+		}
 		c->flags |= new_flags;
 		return;
 	} else if (needed)
 		log_debug("%s: redraw needed", c->name);
 
 	flags = tty->flags & (TTY_BLOCK|TTY_FREEZE|TTY_NOCURSOR);
-	tty->flags = (tty->flags & ~(TTY_BLOCK|TTY_FREEZE)) | TTY_NOCURSOR;
+	tty->flags = (tty->flags & ~(TTY_BLOCK|TTY_FREEZE))|TTY_NOCURSOR;
 
 	if (~c->flags & CLIENT_REDRAWWINDOW) {
 		/*
 		 * If not redrawing the entire window, check whether each pane
 		 * needs to be redrawn.
 		 */
-		TAILQ_FOREACH(wp, &c->session->curw->window->panes, entry) {
-			if (wp->flags & PANE_REDRAW) {
-				log_debug("%s: redrawing pane %%%u", __func__, wp->id);
-				tty_update_mode(tty, mode, NULL);
-				screen_redraw_pane(c, wp);
-			}
+		TAILQ_FOREACH(wp, &w->panes, entry) {
+			redraw = 0;
+			if (wp->flags & PANE_REDRAW)
+				redraw = 1;
+			else if (c->flags & CLIENT_REDRAWPANES)
+				redraw = !!(c->redraw_panes & (1 << bit));
+			if (!redraw)
+				continue;
+			log_debug("%s: redrawing pane %%%u", __func__, wp->id);
+			tty_update_mode(tty, mode, NULL);
+			screen_redraw_pane(c, wp);
 		}
 		c->flags &= ~CLIENT_REDRAWPANES;
 	}
@@ -1752,9 +1777,9 @@ server_client_check_redraw(struct client *c)
 		screen_redraw_screen(c);
 	}
 
-	tty->flags = (tty->flags & ~TTY_NOCURSOR) | (flags & TTY_NOCURSOR);
+	tty->flags = (tty->flags & ~TTY_NOCURSOR)|(flags & TTY_NOCURSOR);
 	tty_update_mode(tty, mode, NULL);
-	tty->flags = (tty->flags & ~(TTY_BLOCK|TTY_FREEZE|TTY_NOCURSOR)) | flags;
+	tty->flags = (tty->flags & ~(TTY_BLOCK|TTY_FREEZE|TTY_NOCURSOR))|flags;
 
 	c->flags &= ~(CLIENT_ALLREDRAWFLAGS|CLIENT_STATUSFORCE);
 
diff --git a/tmux.h b/tmux.h
index 1580e4c1..bbac756b 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1562,6 +1562,8 @@ struct client {
 	int		 flags;
 	struct key_table *keytable;
 
+	uint64_t	 redraw_panes;
+
 	char		*message_string;
 	struct event	 message_timer;
 	u_int		 message_next;