From 3de9afc4a94932993532cb263ebbcd843865181d Mon Sep 17 00:00:00 2001
From: Markus Sauermann <6299227+Sauermann@users.noreply.github.com>
Date: Thu, 23 Nov 2023 23:25:00 +0100
Subject: [PATCH] Fix crash when hiding a Control during mouse-entering

gui.mouse_over can be set to `nullptr` in the `NOTIFICATION_MOUSE_ENTER`-
user-callback a few lines above. This case was previously not handled.
---
 scene/main/viewport.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index 43bdb1395b6..e9ea09a3b1c 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -3207,7 +3207,9 @@ void Viewport::_update_mouse_over(Vector2 p_pos) {
 			}
 
 			// Send Mouse Enter Self notification.
-			gui.mouse_over->notification(Control::NOTIFICATION_MOUSE_ENTER_SELF);
+			if (gui.mouse_over) {
+				gui.mouse_over->notification(Control::NOTIFICATION_MOUSE_ENTER_SELF);
+			}
 
 			notify_embedded_viewports = true;
 		}