--- screen-write.c.orig	2023-12-12 21:17:02.960288969 +0100

+++ screen-write.c	2023-12-12 21:18:07.498869550 +0100

@@ -2120,6 +2120,10 @@

 			return (0);

 	}

+    /* Check if this combined character would be too long. */

+    if (last.data.size + ud->size > sizeof last.data.data)

+        return (0);

+

 	/* Combining; flush any pending output. */

 	screen_write_collect_flush(ctx, 0, __func__);