core: Add is_root parameter to MovieClip::replace_with_movie

The method MovieClip::replace_with_movie accepts an
Option<Arc<SwfMovie>>. If no movie is given, an empty stub movie is
generated and used.
Previously, the IS_ROOT flag has been set for the new replaced SwfMovie,
depending on whether a movie was given to the method or not.
However, there are cases where an explicitely given movie should not be
set as a root movie (e.g. if a specific empty stub movie is given to the
method). Conversely, there are also cases where no movie is given, but
the stub movie should still be set as a root movie (e.g. in specific
MovieClip states).
Therefore, an is_root parameter has been added to the method. This
explicit parameter is now used to set the flag for the new replaced
SwfMovie.

All calls of replace_with_movie have been adapted to use the new
parameter correctly.

core/src/display_object/movie_clip.rs

@@ -386,20 +386,20 @@ impl<'gc> MovieClip<'gc> {
 
     /// Replace the current MovieClipData with a completely new SwfMovie.
     ///
+    /// If no movie is provided, then the movie clip will be replaced with an
+    /// empty movie of the same SWF version.
+    ///
     /// Playback will start at position zero, any existing streamed audio will
     /// be terminated, and so on. Children and AVM data will NOT be kept across
     /// the load boundary.
-    ///
-    /// If no movie is provided, then the movie clip will be replaced with an
-    /// empty movie of the same SWF version.
     pub fn replace_with_movie(
         self,
         context: &mut UpdateContext<'_, 'gc>,
         movie: Option<Arc<SwfMovie>>,
+        is_root: bool,
         loader_info: Option<LoaderInfoObject<'gc>>,
     ) {
         let mut mc = self.0.write(context.gc_context);
-        let is_swf = movie.is_some();
         let movie = movie.unwrap_or_else(|| Arc::new(SwfMovie::empty(mc.movie().version())));
         let total_frames = movie.num_frames();
         assert_eq!(
@@ -420,7 +420,7 @@ impl<'gc> MovieClip<'gc> {
         );
         mc.tag_stream_pos = 0;
         mc.flags = MovieClipFlags::PLAYING;
-        mc.base.base.set_is_root(is_swf);
+        mc.base.base.set_is_root(is_root);
         mc.current_frame = 0;
         mc.audio_stream = None;
         mc.container = ChildContainer::new();
@@ -2476,7 +2476,7 @@ impl<'gc> MovieClip<'gc> {
             None
         };
 
-        self.replace_with_movie(context, movie, None);
+        self.replace_with_movie(context, movie, self.is_root(), None);
     }
 }
 

core/src/loader.rs

@@ -860,7 +860,7 @@ impl<'gc> Loader<'gc> {
                     if !uc.is_action_script_3() {
                         mc.avm1_unload(uc);
                     }
-                    mc.replace_with_movie(uc, None, None);
+                    mc.replace_with_movie(uc, None, false, None);
                 }
 
                 // NOTE: We do NOT call `movie_loader_start` as `loadBytes` does
@@ -1576,7 +1576,12 @@ impl<'gc> Loader<'gc> {
                         // Store our downloaded `SwfMovie` into our target `MovieClip`,
                         // and initialize it.
 
-                        mc.replace_with_movie(&mut activation.context, Some(movie), loader_info);
+                        mc.replace_with_movie(
+                            &mut activation.context,
+                            Some(movie),
+                            true,
+                            loader_info,
+                        );
                     }
 
                     // NOTE: Certain tests specifically expect small files to preload immediately
@@ -1847,7 +1852,7 @@ impl<'gc> Loader<'gc> {
             // This is a load of an image into AVM1 - add it as a child of the target clip.
             if dobj.as_movie_clip().is_none() {
                 let mc = target_clip.as_movie_clip().unwrap();
-                mc.replace_with_movie(uc, Some(movie.unwrap()), None);
+                mc.replace_with_movie(uc, Some(movie.unwrap()), true, None);
                 mc.replace_at_depth(uc, dobj, 1);
 
                 // This sets the MovieClip image state correctly.
@@ -2020,7 +2025,7 @@ impl<'gc> Loader<'gc> {
                     let mut initial_loading_movie = SwfMovie::empty(current_version);
                     initial_loading_movie.set_url(current_url.to_string());
 
-                    mc.replace_with_movie(uc, Some(Arc::new(initial_loading_movie)), None);
+                    mc.replace_with_movie(uc, Some(Arc::new(initial_loading_movie)), true, None);
 
                     // Maybe this (keeping the current URL) should be the default behaviour
                     // of replace_with_movie?
@@ -2057,7 +2062,7 @@ impl<'gc> Loader<'gc> {
 
         let error_movie = SwfMovie::error_movie(swf_url);
         // This also sets total_frames correctly
-        mc.replace_with_movie(uc, Some(Arc::new(error_movie)), None);
+        mc.replace_with_movie(uc, Some(Arc::new(error_movie)), true, None);
         mc.set_cur_preload_frame(uc.gc_context, 0);
     }