From fedd4440f0760ba55a0aff2f917ccc033b930ade Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Tue, 17 Feb 2026 07:42:58 +0000
Subject: [PATCH] Reuse extended entry when clearing RGB cell, to prevent
 memory growth when cells are repeatedly cleared (they are only compacted when
 scrolled off screen). From Michael K Darling in GitHub issue 4862.

---
 grid.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/grid.c b/grid.c
index 258561ce..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 {