From c0047023e6c1f3ca95f03371ddf9de716a466e97 Mon Sep 17 00:00:00 2001
From: lupoDharkael <izhe@hotmail.es>
Date: Mon, 6 Apr 2020 13:22:31 +0200
Subject: [PATCH] NoiseTexture: prevent race condition because of Ref::unref()

(cherry picked from commit 1f0f0b8cea138ecda5e2cd36db50f76cd4bbab01)
---
 modules/opensimplex/noise_texture.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/modules/opensimplex/noise_texture.cpp b/modules/opensimplex/noise_texture.cpp
index aa1c8228139..b924f11e9a8 100644
--- a/modules/opensimplex/noise_texture.cpp
+++ b/modules/opensimplex/noise_texture.cpp
@@ -135,14 +135,19 @@ void NoiseTexture::_queue_update() {
 
 Ref<Image> NoiseTexture::_generate_texture() {
 
-	if (noise.is_null()) return Ref<Image>();
+	// Prevent memdelete due to unref() on other thread.
+	Ref<OpenSimplexNoise> ref_noise = noise;
+
+	if (ref_noise.is_null()) {
+		return Ref<Image>();
+	}
 
 	Ref<Image> image;
 
 	if (seamless) {
-		image = noise->get_seamless_image(size.x);
+		image = ref_noise->get_seamless_image(size.x);
 	} else {
-		image = noise->get_image(size.x, size.y);
+		image = ref_noise->get_image(size.x, size.y);
 	}
 
 	if (as_normalmap) {