core: More mixed AVM fixes, improve test

This commit breaks mixed AVM without #13889.

core/src/display_object/container.rs

@@ -381,15 +381,18 @@ pub trait TDisplayObjectContainer<'gc>:
     /// Insert a child directly into this container's depth list.
     fn insert_child_into_depth_list(
         &mut self,
-        gc_context: &Mutation<'gc>,
+        context: &mut UpdateContext<'_, 'gc>,
         depth: Depth,
         child: DisplayObject<'gc>,
     ) {
-        self.raw_container_mut(gc_context)
+        let this: DisplayObject<'_> = (*self).into();
+
+        child.set_depth(context.gc_context, depth);
+        child.set_parent(context, Some(this));
+        self.raw_container_mut(context.gc_context)
             .insert_child_into_depth_list(depth, child);
 
-        let this: DisplayObject<'_> = (*self).into();
-        this.invalidate_cached_bitmap(gc_context);
+        this.invalidate_cached_bitmap(context.gc_context);
     }
 
     /// Removes (without unloading) a child display object from this container's depth list.

core/src/loader.rs

@@ -42,6 +42,9 @@ use url::{form_urlencoded, ParseError, Url};
 
 pub type Handle = Index;
 
+/// The depth of AVM1 movies that AVM2 loads.
+const LOADER_INSERTED_AVM1_DEPTH: i32 = -0xF000;
+
 /// How Ruffle should load movies.
 #[cfg_attr(feature = "clap", derive(clap::ValueEnum))]
 #[derive(Debug, Clone, Copy, PartialEq)]
@@ -1730,6 +1733,8 @@ impl<'gc> Loader<'gc> {
                         {
                             // When an AVM2 movie loads an AVM1 movie, we need to call `post_instantiation` here.
                             mc.post_instantiation(uc, None, Instantiator::Movie, false);
+
+                            mc.set_depth(uc.gc_context, LOADER_INSERTED_AVM1_DEPTH);
                         }
                     }
 
@@ -2007,8 +2012,8 @@ impl<'gc> Loader<'gc> {
 
             if !movie.unwrap().is_action_script_3() {
                 loader.insert_child_into_depth_list(
-                    activation.context.gc_context,
-                    0,
+                    &mut activation.context,
+                    LOADER_INSERTED_AVM1_DEPTH,
                     dobj.unwrap(),
                 );
             }

tests/tests/swfs/avm2/mixed_avm/output.txt

@@ -1,5 +1,11 @@
 Starting load...
+_global access in DoInitAction: 
+[type Object]
+root depth:
+-77824
 hello from avm1!
+Root depth: -77824
+_root == _level0: false
 [object AVM1Movie]
 [object ApplicationDomain]
 Load complete!