From 2f8673dc0717a3000bbbf9d0d8b88dafe5d69769 Mon Sep 17 00:00:00 2001
From: Markus Sauermann <6299227+Sauermann@users.noreply.github.com>
Date: Wed, 2 Aug 2023 21:17:42 +0200
Subject: [PATCH] Handle potential platform-specific `Window` mouse-enter/exit
 bugs gracefully

Also replace `DEV_ASSERT` by `WARN_PRINT_ONCE`.
---
 scene/main/window.cpp | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/scene/main/window.cpp b/scene/main/window.cpp
index bd51f8eeaf0c..bf299b63e59b 100644
--- a/scene/main/window.cpp
+++ b/scene/main/window.cpp
@@ -670,9 +670,14 @@ void Window::_propagate_window_notification(Node *p_node, int p_notification) {
 void Window::_event_callback(DisplayServer::WindowEvent p_event) {
 	switch (p_event) {
 		case DisplayServer::WINDOW_EVENT_MOUSE_ENTER: {
-			_propagate_window_notification(this, NOTIFICATION_WM_MOUSE_ENTER);
 			Window *root = get_tree()->get_root();
-			DEV_ASSERT(!root->gui.windowmanager_window_over); // Entering a window while a window is hovered should never happen.
+			if (root->gui.windowmanager_window_over) {
+#ifdef DEV_ENABLED
+				WARN_PRINT_ONCE("Entering a window while a window is hovered should never happen in DisplayServer.");
+#endif // DEV_ENABLED
+				root->gui.windowmanager_window_over->_event_callback(DisplayServer::WINDOW_EVENT_MOUSE_EXIT);
+			}
+			_propagate_window_notification(this, NOTIFICATION_WM_MOUSE_ENTER);
 			root->gui.windowmanager_window_over = this;
 			notification(NOTIFICATION_VP_MOUSE_ENTER);
 			if (DisplayServer::get_singleton()->has_feature(DisplayServer::FEATURE_CURSOR_SHAPE)) {
@@ -681,7 +686,12 @@ void Window::_event_callback(DisplayServer::WindowEvent p_event) {
 		} break;
 		case DisplayServer::WINDOW_EVENT_MOUSE_EXIT: {
 			Window *root = get_tree()->get_root();
-			DEV_ASSERT(root->gui.windowmanager_window_over); // Exiting a window, while no window is hovered should never happen.
+			if (!root->gui.windowmanager_window_over) {
+#ifdef DEV_ENABLED
+				WARN_PRINT_ONCE("Exiting a window while no window is hovered should never happen in DisplayServer.");
+#endif // DEV_ENABLED
+				return;
+			}
 			root->gui.windowmanager_window_over->_mouse_leave_viewport();
 			root->gui.windowmanager_window_over = nullptr;
 			_propagate_window_notification(this, NOTIFICATION_WM_MOUSE_EXIT);