From afb95f3134567888c03bc45136ac2d6d5dcfd9cc Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Sun, 26 Jul 2026 09:02:08 +0000
Subject: [PATCH] Do not loop forever if the combining character is too long,
 GitHub issue 5434 from me at qdrs dot dev.

---
 screen-write.c | 4 ++--
 tty-draw.c     | 4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/screen-write.c b/screen-write.c
index 1ba5bed70..6cfc80ad0 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: screen-write.c,v 1.284 2026/07/20 11:16:33 nicm Exp $ */
+/* $OpenBSD: screen-write.c,v 1.285 2026/07/26 09:02:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -2783,7 +2783,7 @@ screen_write_combine(struct screen_write_ctx *ctx, const struct grid_cell *gc)
 
 	/* Check if this combined character would be too long. */
 	if (last.data.size + ud->size > sizeof last.data.data)
-		return (0);
+		return (zero_width);
 
 	/* Combining; flush any pending output. */
 	screen_write_collect_flush(ctx, 0, __func__);
diff --git a/tty-draw.c b/tty-draw.c
index d47be66bc..06d520e11 100644
--- a/tty-draw.c
+++ b/tty-draw.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tty-draw.c,v 1.14 2026/06/19 10:38:29 nicm Exp $ */
+/* $OpenBSD: tty-draw.c,v 1.15 2026/07/26 09:02:08 nicm Exp $ */
 
 /*
  * Copyright (c) 2026 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -100,6 +100,8 @@ tty_draw_line_get_empty(const struct grid_cell *gc,
 		empty = nx;
 	else if (gc->flags & GRID_FLAG_PADDING)
 		empty = 1;
+	else if (gc->data.width == 0)
+		empty = 1;
 	else if (gc->flags & GRID_FLAG_SELECTED)
 		empty = 0;
 	else if (gc->bg == last->bg && gc->attr == 0 && gc->link == 0) {