Fix AudioStreamPlayer2D crash when PhysicsServer2D runs on thread

Fixes AudioStreamPlayer2D crash when PhysicsServer2D runs on thread due to empty PhysicsSpace

(cherry picked from commit a5351086b0eafa659c4f4c88471d183cd991b45e)

2 files changed, 7 insertions, 2 deletions

diff --git a/scene/2d/audio_stream_player_2d.cpp b/scene/2d/audio_stream_player_2d.cpp
index c175edb6cb..466ffad951 100644
--- a/scene/2d/audio_stream_player_2d.cpp
+++ b/scene/2d/audio_stream_player_2d.cpp
@@ -68,7 +68,8 @@ void AudioStreamPlayer2D::_notification(int p_what) {
 
 		case NOTIFICATION_INTERNAL_PHYSICS_PROCESS: {
 			// Update anything related to position first, if possible of course.
-			if (setplay.get() > 0 || (active.is_set() && last_mix_count != AudioServer::get_singleton()->get_mix_count())) {
+			if (setplay.get() > 0 || (active.is_set() && last_mix_count != AudioServer::get_singleton()->get_mix_count()) || force_update_panning) {
+				force_update_panning = false;
 				_update_panning();
 			}
 
@@ -109,6 +110,7 @@ void AudioStreamPlayer2D::_notification(int p_what) {
 	}
 }
 
+// Interacts with PhysicsServer2D, so can only be called during _physics_process
 StringName AudioStreamPlayer2D::_get_actual_bus() {
 	Vector2 global_pos = get_global_position();
 
@@ -117,6 +119,7 @@ StringName AudioStreamPlayer2D::_get_actual_bus() {
 	ERR_FAIL_COND_V(world_2d.is_null(), SNAME("Master"));
 
 	PhysicsDirectSpaceState2D *space_state = PhysicsServer2D::get_singleton()->space_get_direct_state(world_2d->get_space());
+	ERR_FAIL_COND_V(space_state == nullptr, SNAME("Master"));
 	PhysicsDirectSpaceState2D::ShapeResult sr[MAX_INTERSECT_AREAS];
 
 	PhysicsDirectSpaceState2D::PointParameters point_params;
@@ -142,6 +145,7 @@ StringName AudioStreamPlayer2D::_get_actual_bus() {
 	return default_bus;
 }
 
+// Interacts with PhysicsServer2D, so can only be called during _physics_process
 void AudioStreamPlayer2D::_update_panning() {
 	if (!active.is_set() || stream.is_null()) {
 		return;
diff --git a/scene/2d/audio_stream_player_2d.h b/scene/2d/audio_stream_player_2d.h
index 79a026fed2..9b23fd3943 100644
--- a/scene/2d/audio_stream_player_2d.h
+++ b/scene/2d/audio_stream_player_2d.h
@@ -61,6 +61,7 @@ private:
 	Vector<AudioFrame> volume_vector;
 
 	uint64_t last_mix_count = -1;
+	bool force_update_panning = false;
 
 	float volume_db = 0.0;
 	float pitch_scale = 1.0;
@@ -75,7 +76,7 @@ private:
 	void _update_panning();
 	void _bus_layout_changed();
 
-	static void _listener_changed_cb(void *self) { reinterpret_cast<AudioStreamPlayer2D *>(self)->_update_panning(); }
+	static void _listener_changed_cb(void *self) { reinterpret_cast<AudioStreamPlayer2D *>(self)->force_update_panning = true; }
 
 	uint32_t area_mask = 1;