Fix side effects of the bookkepping of Area/Area2D's monitoring

- Fix monitoring flag being reset when the scene is out of the tree (happens on save all if the current scene is not the focused one, therefore on save-on-run as well)
- Fix the inability to reset the monitoring flag while the area is out of the tree

1 files changed, 12 insertions, 8 deletions

diff --git a/scene/2d/area_2d.cpp b/scene/2d/area_2d.cpp
index 1a53f684e..cea9cd8da 100644
--- a/scene/2d/area_2d.cpp
+++ b/scene/2d/area_2d.cpp
@@ -380,10 +380,6 @@ void Area2D::_notification(int p_what) {
 
 	switch (p_what) {
 
-		case NOTIFICATION_READY: {
-
-			is_ready = true;
-		} break;
 		case NOTIFICATION_EXIT_TREE: {
 
 			monitoring_stored = monitoring;
@@ -391,16 +387,25 @@ void Area2D::_notification(int p_what) {
 			_clear_monitoring();
 		} break;
 		case NOTIFICATION_ENTER_TREE: {
-			if (is_ready)
-				set_enable_monitoring(monitoring_stored);
+
+			if (monitoring_stored) {
+				set_enable_monitoring(true);
+				monitoring_stored = false;
+			}
 		} break;
 	}
 }
 
 void Area2D::set_enable_monitoring(bool p_enable) {
 
+	if (!is_inside_tree()) {
+		monitoring_stored = p_enable;
+		return;
+	}
+
 	if (p_enable == monitoring)
 		return;
+
 	if (locked) {
 		ERR_EXPLAIN("Function blocked during in/out signal. Use call_deferred(\"set_enable_monitoring\",true/false)");
 	}
@@ -422,7 +427,7 @@ void Area2D::set_enable_monitoring(bool p_enable) {
 
 bool Area2D::is_monitoring_enabled() const {
 
-	return monitoring;
+	return monitoring || monitoring_stored;
 }
 
 void Area2D::set_monitorable(bool p_enable) {
@@ -651,7 +656,6 @@ Area2D::Area2D()
 	collision_mask = 1;
 	layer_mask = 1;
 	monitoring_stored = false;
-	is_ready = false;
 	set_enable_monitoring(true);
 	set_monitorable(true);
 }