From 0a5a6cb7fa58577989716976a3430a9de4cac860 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Sun, 4 Oct 2020 19:28:22 +0200
Subject: [PATCH] sixel: scroll up/down: early return when list is empty
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Branch tagged as ‘likely’ for performance reason
---
 sixel.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/sixel.c b/sixel.c
index ee34df0a..76b42b25 100644
--- a/sixel.c
+++ b/sixel.c
@@ -242,6 +242,9 @@ out:
 void
 sixel_scroll_up(struct terminal *term, int rows)
 {
+    if (likely(tll_length(term->grid->sixel_images) == 0))
+        return;
+
     tll_rforeach(term->grid->sixel_images, it) {
         struct sixel *six = &it->item;
 
@@ -269,6 +272,9 @@ sixel_scroll_up(struct terminal *term, int rows)
 void
 sixel_scroll_down(struct terminal *term, int rows)
 {
+    if (likely(tll_length(term->grid->sixel_images) == 0))
+        return;
+
     assert(term->grid->num_rows >= rows);
 
     tll_foreach(term->grid->sixel_images, it) {