core: Store the root of each loaded movie and use it as a last-ditch way to get the root

core/src/avm2/globals/flash/display/displayobject.rs

@@ -403,7 +403,7 @@ pub fn root<'gc>(
 ) -> Result<Value<'gc>, Error> {
     if let Some(dobj) = this.and_then(|this| this.as_display_object()) {
         return Ok(dobj
-            .avm2_root(&activation.context)
+            .avm2_root(&mut activation.context)
             .map(|root| root.object2())
             .unwrap_or(Value::Null));
     }
@@ -558,7 +558,7 @@ pub fn loader_info<'gc>(
     _args: &[Value<'gc>],
 ) -> Result<Value<'gc>, Error> {
     if let Some(dobj) = this.and_then(|this| this.as_display_object()) {
-        if let Some(root) = dobj.avm2_root(&activation.context) {
+        if let Some(root) = dobj.avm2_root(&mut activation.context) {
             if DisplayObject::ptr_eq(root, dobj) {
                 let movie = dobj.movie();
 

core/src/display_object.rs

@@ -1254,7 +1254,7 @@ pub trait TDisplayObject<'gc>:
     ///
     /// This function implements the AVM2 concept of root clips. For the AVM1
     /// version, see `avm1_root`.
-    fn avm2_root(&self, context: &UpdateContext<'_, 'gc, '_>) -> Option<DisplayObject<'gc>> {
+    fn avm2_root(&self, context: &mut UpdateContext<'_, 'gc, '_>) -> Option<DisplayObject<'gc>> {
         let mut parent = Some((*self).into());
 
         while let Some(p) = parent {
@@ -1280,17 +1280,8 @@ pub trait TDisplayObject<'gc>:
         }
 
         parent.or_else(|| {
-            if let Avm1Value::Object(object) = self.object() {
+            let movie = self.movie()?;
-                object.as_display_object()
+            context.library.library_for_movie_mut(movie).root()
-            } else if let Avm2Value::Object(object) = self.object2() {
-                if self.is_on_stage(context) {
-                    object.as_display_object()
-                } else {
-                    None
-                }
-            } else {
-                None
-            }
         })
     }
 

core/src/library.rs

@@ -143,6 +143,9 @@ pub struct MovieLibrary<'gc> {
     /// Shared reference to the constructor registry used for this movie.
     /// Should be `None` if this is an AVM2 movie.
     avm1_constructor_registry: Option<Gc<'gc, Avm1ConstructorRegistry<'gc>>>,
+
+    /// The root display object for this movie.
+    root: Option<DisplayObject<'gc>>,
 }
 
 impl<'gc> MovieLibrary<'gc> {
@@ -155,6 +158,7 @@ impl<'gc> MovieLibrary<'gc> {
             avm_type,
             avm2_domain: None,
             avm1_constructor_registry: None,
+            root: None,
         }
     }
 
@@ -361,6 +365,18 @@ impl<'gc> MovieLibrary<'gc> {
     pub fn avm2_domain(&self) -> Avm2Domain<'gc> {
         self.avm2_domain.unwrap()
     }
+
+    /// Retrieve the root display object that was created to represent the
+    /// movie being loaded.
+    pub fn root(&self) -> Option<DisplayObject<'gc>> {
+        self.root
+    }
+
+    /// Set the root display object that was created to represent the
+    /// movie being loaded.
+    pub fn set_root(&mut self, root: DisplayObject<'gc>) {
+        self.root = Some(root);
+    }
 }
 
 /// Symbol library for multiple movies.

core/src/loader.rs

@@ -488,12 +488,6 @@ impl<'gc> Loader<'gc> {
                     .lock()
                     .expect("Could not lock player!!")
                     .update(|uc| {
-                        let domain =
-                            Avm2Domain::movie_domain(uc.gc_context, uc.avm2.global_domain());
-                        uc.library
-                            .library_for_movie_mut(movie.clone())
-                            .set_avm2_domain(domain);
-
                         let (clip, broadcaster) = match uc.load_manager.get_loader(handle) {
                             Some(Loader::Movie {
                                 target_clip,
@@ -504,6 +498,13 @@ impl<'gc> Loader<'gc> {
                             _ => unreachable!(),
                         };
 
+                        let domain =
+                            Avm2Domain::movie_domain(uc.gc_context, uc.avm2.global_domain());
+                        let library = uc.library.library_for_movie_mut(movie.clone());
+
+                        library.set_avm2_domain(domain);
+                        library.set_root(clip);
+
                         if let Some(broadcaster) = broadcaster {
                             Avm1::run_stack_frame_for_method(
                                 clip,

core/src/player.rs

@@ -386,14 +386,14 @@ impl Player {
                 context.swf.height(),
             );
             let domain = Avm2Domain::movie_domain(context.gc_context, context.avm2.global_domain());
-            context
-                .library
-                .library_for_movie_mut(context.swf.clone())
-                .set_avm2_domain(domain);
-
             let root: DisplayObject =
                 MovieClip::from_movie(context.gc_context, context.swf.clone()).into();
 
+            let library = context.library.library_for_movie_mut(context.swf.clone());
+
+            library.set_avm2_domain(domain);
+            library.set_root(root);
+
             root.set_depth(context.gc_context, 0);
             let flashvars = if !context.swf.parameters().is_empty() {
                 let object = ScriptObject::object(context.gc_context, None);