From 5d576fccbaef3e413bcb5b7a98708d2f1904f5d7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Tue, 20 Jun 2023 14:52:17 +0200
Subject: [PATCH] sixel: regression: linefeed count for chunked up sixel image

All image chunks but the last *should* scroll the screen content.
---
 sixel.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sixel.c b/sixel.c
index a40a54a4..29585d71 100644
--- a/sixel.c
+++ b/sixel.c
@@ -1049,7 +1049,12 @@ sixel_unhook(struct terminal *term)
 
         if (do_scroll) {
              /* Yes, truncate last row. This matches XTerm’s, and VT382’s behavior */
-            const int linefeed_count = (image.height - 6 * term->sixel.pan + 1) / term->cell_height;
+            const int linefeed_count = rows_avail == 0
+                ? (image.height - 6 * term->sixel.pan + 1) / term->cell_height
+                : image.height / term->cell_height;
+
+            xassert(rows_avail == 0 || image.height % term->cell_height == 0);
+
             for (size_t i = 0; i < linefeed_count; i++)
                 term_linefeed(term);