avm2: Ensure that objects are only *ever* constructed at frame construction time.

This ensures that root movie classes see their children in their constructor.

core/src/display_object/movie_clip.rs

@@ -78,6 +78,7 @@ pub struct MovieClipData<'gc> {
     has_button_clip_event: bool,
     flags: MovieClipFlags,
     avm2_constructor: Option<Avm2Object<'gc>>,
+    avm2_constructor_ran: bool,
     drawing: Drawing,
     is_focusable: bool,
     has_focus: bool,
@@ -105,6 +106,7 @@ impl<'gc> MovieClip<'gc> {
                 has_button_clip_event: false,
                 flags: MovieClipFlags::empty(),
                 avm2_constructor: None,
+                avm2_constructor_ran: false,
                 drawing: Drawing::new(),
                 is_focusable: false,
                 has_focus: false,
@@ -137,6 +139,7 @@ impl<'gc> MovieClip<'gc> {
                 has_button_clip_event: false,
                 flags: MovieClipFlags::empty(),
                 avm2_constructor: Some(constr),
+                avm2_constructor_ran: false,
                 drawing: Drawing::new(),
                 is_focusable: false,
                 has_focus: false,
@@ -172,6 +175,7 @@ impl<'gc> MovieClip<'gc> {
                 has_button_clip_event: false,
                 flags: MovieClipFlags::PLAYING,
                 avm2_constructor: None,
+                avm2_constructor_ran: false,
                 drawing: Drawing::new(),
                 is_focusable: false,
                 has_focus: false,
@@ -595,8 +599,6 @@ impl<'gc> MovieClip<'gc> {
                         if id == 0 {
                             //TODO: This assumes only the root movie has `SymbolClass` tags.
                             self.set_avm2_constructor(activation.context.gc_context, Some(proto));
-                            self.allocate_as_avm2_object(&mut activation.context, self.into());
-                            self.construct_as_avm2_object(&mut activation.context);
                         } else if let Some(Character::MovieClip(mc)) = library.character_by_id(id) {
                             mc.set_avm2_constructor(activation.context.gc_context, Some(proto))
                         } else {
@@ -1576,6 +1578,8 @@ impl<'gc> MovieClip<'gc> {
                 log::error!("Got {} when constructing AVM2 side of display object", e);
             }
         }
+
+        self.0.write(context.gc_context).avm2_constructor_ran = true;
     }
 
     pub fn register_frame_script(
@@ -1711,6 +1715,10 @@ impl<'gc> TDisplayObject<'gc> for MovieClip<'gc> {
                 };
                 let _ = tag_utils::decode_tags(&mut reader, tag_callback, TagCode::ShowFrame);
             }
+
+            if !self.0.read().avm2_constructor_ran {
+                self.construct_as_avm2_object(context);
+            }
         }
     }
 
@@ -2010,9 +2018,7 @@ impl<'gc> TDisplayObject<'gc> for MovieClip<'gc> {
         self.set_default_instance_name(context);
 
         let vm_type = self.vm_type(context);
-        if vm_type == AvmType::Avm2 {
-            self.construct_as_avm2_object(context);
-        } else if vm_type == AvmType::Avm1 {
+        if vm_type == AvmType::Avm1 {
             self.construct_as_avm1_object(
                 context,
                 display_object,

core/src/player.rs

@@ -409,7 +409,7 @@ impl Player {
             } else {
                 None
             };
-            root.construct_frame(context);
+
             root.post_instantiation(context, root, flashvars, Instantiator::Movie, false);
             root.set_default_root_name(context);
             context.levels.insert(0, root);

core/tests/regression_tests.rs

@@ -548,6 +548,7 @@ swf_tests! {
     (as3_loaderinfo_quine, "avm2/loaderinfo_quine", 2),
     (nan_scale, "avm1/nan_scale", 1),
     (as3_nan_scale, "avm2/nan_scale", 1),
+    (as3_documentclass, "avm2/documentclass", 1),
 }
 
 // TODO: These tests have some inaccuracies currently, so we use approx_eq to test that numeric values are close enough.

core/tests/swfs/avm2/documentclass/Child.as

@@ -0,0 +1,11 @@
+package {
+	import flash.display.MovieClip;
+
+	public class Child extends MovieClip {
+		public function Child() {
+			trace("/// Child constructor");
+			trace("/// this.b");
+			trace(this.b);
+		}
+	}
+}

core/tests/swfs/avm2/documentclass/Grandchild.as

@@ -0,0 +1,9 @@
+package {
+	import flash.display.MovieClip;
+
+	public class Grandchild extends MovieClip {
+		public function Grandchild() {
+			trace("/// Grandchild constructor");
+		}
+	}
+}

core/tests/swfs/avm2/documentclass/Main.as

@@ -0,0 +1,13 @@
+package {
+	import flash.display.MovieClip;
+
+	public class Main extends MovieClip {
+		public function Main() {
+			trace("/// Main constructor");
+			trace("/// this.a");
+			trace(this.a);
+			trace("/// this.a.b");
+			trace(this.a.b);
+		}
+	}
+}

core/tests/swfs/avm2/documentclass/output.txt

@@ -0,0 +1,9 @@
+/// Grandchild constructor
+/// Child constructor
+/// this.b
+[object Grandchild]
+/// Main constructor
+/// this.a
+[object Child]
+/// this.a.b
+[object Grandchild]