From e9f205f952efac448974239526c5284134ae41b9 Mon Sep 17 00:00:00 2001
From: sfan5 <sfan5@live.de>
Date: Mon, 12 Sep 2022 16:19:44 +0200
Subject: [PATCH] Avoid using XIWarpPointer on certain setups where it's broken

fixes minetest/minetest#12697
---
 source/Irrlicht/CIrrDeviceLinux.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/source/Irrlicht/CIrrDeviceLinux.cpp b/source/Irrlicht/CIrrDeviceLinux.cpp
index 6d4c1a7c..d500af06 100644
--- a/source/Irrlicht/CIrrDeviceLinux.cpp
+++ b/source/Irrlicht/CIrrDeviceLinux.cpp
@@ -2118,7 +2118,17 @@ CIrrDeviceLinux::CCursorControl::CCursorControl(CIrrDeviceLinux* dev, bool null)
 	if (!Null)
 	{
 #ifdef _IRR_LINUX_X11_XINPUT2_
-		XIGetClientPointer(Device->XDisplay, Device->XWindow, &DeviceId);
+		// XIWarpPointer is entirely broken on multi-head setups (see also [1]),
+		// but behaves better in other cases so we can't just disable it outright.
+		// [1] https://developer.blender.org/rB165caafb99c6846e53d11c4e966990aaffc06cea
+		if (XScreenCount(Device->XDisplay) > 1)
+		{
+			os::Printer::log("Detected classic multi-head setup, not using XIWarpPointer");
+		}
+		else
+		{
+			XIGetClientPointer(Device->XDisplay, Device->XWindow, &DeviceId);
+		}
 #endif
 
 		XGCValues values;