From 7d89e5d84cbbfad87afca8b6eca3ee04e3877789 Mon Sep 17 00:00:00 2001
From: Henrik Rydgard <hrydgard@gmail.com>
Date: Thu, 4 May 2017 00:30:04 +0200
Subject: [PATCH] Experiment (#9647): Prevent NaN values from getting into the
 UI system through TouchInput

---
 UI/NativeApp.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/UI/NativeApp.cpp b/UI/NativeApp.cpp
index c610ccda65..bbcd0980f9 100644
--- a/UI/NativeApp.cpp
+++ b/UI/NativeApp.cpp
@@ -945,6 +945,10 @@ bool NativeIsAtTopLevel() {
 
 bool NativeTouch(const TouchInput &touch) {
 	if (screenManager) {
+		// Brute force prevent NaNs from getting into the UI system
+		if (my_isnan(touch.x) || my_isnan(touch.y)) {
+			return false;
+		}
 		screenManager->touch(touch);
 		return true;
 	} else {