From 40f7d085f4a04a6e76a861de3f9ba99504d979c2 Mon Sep 17 00:00:00 2001
From: Michael Lutz <michi@icosahedron.de>
Date: Mon, 12 Apr 2021 21:44:32 +0200
Subject: [PATCH] Fix #9028: [OpenGL] Clear cursor cache on destroying the
 OpenGL backend.

---
 src/video/opengl.cpp | 22 +++++++++++++++-------
 src/video/opengl.h   |  2 ++
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/video/opengl.cpp b/src/video/opengl.cpp
index c1c1afaaec..bb509bcd74 100644
--- a/src/video/opengl.cpp
+++ b/src/video/opengl.cpp
@@ -510,7 +510,7 @@ OpenGLBackend::~OpenGLBackend()
 		_glDeleteBuffers(1, &this->anim_pbo);
 	}
 	if (_glDeleteTextures != nullptr) {
-		ClearCursorCache();
+		this->InternalClearCursorCache();
 		OpenGLSprite::Destroy();
 
 		_glDeleteTextures(1, &this->vid_texture);
@@ -1082,12 +1082,7 @@ void OpenGLBackend::PopulateCursorCache()
 		this->clear_cursor_cache = false;
 		this->last_sprite_pal = (PaletteID)-1;
 
-		Sprite *sp;
-		while ((sp = this->cursor_cache.Pop()) != nullptr) {
-			OpenGLSprite *sprite = (OpenGLSprite *)sp->data;
-			sprite->~OpenGLSprite();
-			free(sp);
-		}
+		this->InternalClearCursorCache();
 	}
 
 	this->cursor_pos = _cursor.pos;
@@ -1113,6 +1108,19 @@ void OpenGLBackend::PopulateCursorCache()
 /**
  * Clear all cached cursor sprites.
  */
+void OpenGLBackend::InternalClearCursorCache()
+{
+	Sprite *sp;
+	while ((sp = this->cursor_cache.Pop()) != nullptr) {
+		OpenGLSprite *sprite = (OpenGLSprite *)sp->data;
+		sprite->~OpenGLSprite();
+		free(sp);
+	}
+}
+
+/**
+ * Queue a request for cursor cache clear.
+ */
 void OpenGLBackend::ClearCursorCache()
 {
 	/* If the game loop is threaded, this function might be called
diff --git a/src/video/opengl.h b/src/video/opengl.h
index 7e42b20bed..b0318f9882 100644
--- a/src/video/opengl.h
+++ b/src/video/opengl.h
@@ -77,6 +77,8 @@ private:
 	const char *Init();
 	bool InitShaders();
 
+	void InternalClearCursorCache();
+
 	void RenderOglSprite(OpenGLSprite *gl_sprite, PaletteID pal, int x, int y, ZoomLevel zoom);
 
 public: