avm1: Allow SharedObject creation even if URL is unknown (fix #2150)

Allow SharedObjects to be created even in the case that the movie
URL is None (for example, loading an SWF from bytes). Use a dummy
"localhost" URL.

core/src/avm1/globals/shared_object.rs

@@ -176,11 +176,16 @@ pub fn get_local<'gc>(
         return Ok(Value::Null);
     };
 
-    let mut movie_url = if let Some(url) = movie.url().and_then(|url| url::Url::parse(url).ok()) {
+    let mut movie_url = if let Some(url) = movie.url() {
+        if let Ok(url) = url::Url::parse(url) {
             url
         } else {
             log::error!("SharedObject::get_local: Unable to parse movie URL");
             return Ok(Value::Null);
+        }
+    } else {
+        // No URL (loading local data). Use a dummy URL to allow SharedObjects to work.
+        url::Url::parse("file://localhost").unwrap()
     };
     movie_url.set_query(None);
     movie_url.set_fragment(None);