From 113aaf37fc5c3b278a50b94c568782f32ae03ef4 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Thu, 13 Nov 2025 13:08:44 +0000
Subject: [PATCH] When copying a line from one screen to another, stop only
 when both source and target are beyond the allocated line length. Fixes
 problems with trailing spaces on pane-border-format. GitHub issue 4688 from
 Dmitry Ryabkov.

---
 screen-write.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/screen-write.c b/screen-write.c
index 8e04681a..43afb50d 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -583,7 +583,8 @@ screen_write_fast_copy(struct screen_write_ctx *ctx, struct screen *src,
 		if (wp != NULL)
 			screen_write_initctx(ctx, &ttyctx, 0);
 		for (xx = px; xx < px + nx; xx++) {
-			if (xx >= grid_get_line(gd, yy)->cellsize)
+			if (xx >= grid_get_line(gd, yy)->cellsize &&
+			    s->cx >= grid_get_line(ctx->s->grid, s->cy)->cellsize)
 				break;
 			grid_get_cell(gd, xx, yy, &gc);
 			if (xx + gc.data.width > px + nx)