SDL: x11: Don't update grab on enter when the mouse is captured (810ad)

SDL Commits
1 
From 810addf7aea58d3d6b1029c93d2f9b120b1ac199 Mon Sep 17 00:00:00 2001
From: Frank Praznik <[EMAIL REDACTED]>
Date: Mon, 5 May 2025 10:55:26 -0400
Subject: [PATCH] x11: Don't update grab on enter when the mouse is captured

The xserver will still send EnterNotify events while the pointer is captured, and the grab shouldn't be updated in these cases, as it will cause the capture to be lost.

(cherry picked from commit 33e5f4885aeb20f74730d8abfcb4c5fb230ba406)
---
 src/video/x11/SDL_x11events.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/video/x11/SDL_x11events.c b/src/video/x11/SDL_x11events.c
index dcc6c878c6ed9..a4e5d9caf67a3 100644
--- a/src/video/x11/SDL_x11events.c
+++ b/src/video/x11/SDL_x11events.c
@@ -1338,8 +1338,10 @@ static void X11_DispatchEvent(SDL_VideoDevice *_this, XEvent *xevent)
             SDL_SendMouseMotion(0, data->window, SDL_GLOBAL_MOUSE_ID, false, (float)xevent->xcrossing.x, (float)xevent->xcrossing.y);
         }
 
-        // We ungrab in LeaveNotify, so we may need to grab again here
-        SDL_UpdateWindowGrab(data->window);
+        // We ungrab in LeaveNotify, so we may need to grab again here, but not if captured, as the capture can be lost.
+        if (!(data->window->flags & SDL_WINDOW_MOUSE_CAPTURE)) {
+            SDL_UpdateWindowGrab(data->window);
+        }
 
         X11_ProcessHitTest(_this, data, mouse->last_x, mouse->last_y, true);
     } break;