SDL: x11: XI_Motion should mark the global mouse position as changed. (949b4)

SDL Commits
1 
From 949b4fc349215eb8f6c16bffb92c2d0f4d4e5553 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Thu, 18 Jan 2024 15:10:16 -0500
Subject: [PATCH] x11: XI_Motion should mark the global mouse position as
 changed.

Otherwise we'll miss it when XWarpPointer() is used. x11vnc may do this to
manage mouse input in some circumstances, so it can be possible for _all_
mouse motion to go through this path, breaking SDL_GetGlobalMouseState().

Thanks to @chrismile for all the detective work to figure this out!

Fixes #8827.

(cherry picked from commit cc7fe8c255ca8f3b4f5407c0c70103b4c7ad8168)
---
 src/video/x11/SDL_x11xinput2.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/video/x11/SDL_x11xinput2.c b/src/video/x11/SDL_x11xinput2.c
index 346130a34fb7..5003937125d5 100644
--- a/src/video/x11/SDL_x11xinput2.c
+++ b/src/video/x11/SDL_x11xinput2.c
@@ -436,6 +436,8 @@ int X11_HandleXinput2Event(SDL_VideoDevice *_this, XGenericEventCookie *cookie)
         int pointer_emulated = (xev->flags & XIPointerEmulated);
 #endif /* SDL_VIDEO_DRIVER_X11_XINPUT2_SUPPORTS_MULTITOUCH */
 
+        videodata->global_mouse_changed = SDL_TRUE;
+
         if (xev->deviceid != xev->sourceid) {
             /* Discard events from "Master" devices to avoid duplicates. */
             return 1;