From 0c879ab28828afdffe0f6a8effb1830fd814868e Mon Sep 17 00:00:00 2001
From: Haoyu Qiu <timothyqiu32@gmail.com>
Date: Mon, 2 Aug 2021 23:07:18 +0800
Subject: [PATCH] Fix crash when number of indices to optimize is not a
 multiple of 3

---
 scene/resources/surface_tool.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/scene/resources/surface_tool.cpp b/scene/resources/surface_tool.cpp
index 9f8c35b668f..875aa30824f 100644
--- a/scene/resources/surface_tool.cpp
+++ b/scene/resources/surface_tool.cpp
@@ -1120,6 +1120,7 @@ SurfaceTool::CustomFormat SurfaceTool::get_custom_format(int p_index) const {
 void SurfaceTool::optimize_indices_for_cache() {
 	ERR_FAIL_COND(optimize_vertex_cache_func == nullptr);
 	ERR_FAIL_COND(index_array.size() == 0);
+	ERR_FAIL_COND(index_array.size() % 3 != 0);
 
 	LocalVector old_index_array = index_array;
 	memset(index_array.ptr(), 0, index_array.size() * sizeof(int));