avm2: XML/XMLList is converted to a string when set as attribute value

core/src/avm2/object/xml_object.rs

@@ -312,15 +312,6 @@ impl<'gc> TObject<'gc> for XmlObject<'gc> {
 
         if name.is_attribute() {
             self.delete_property_local(activation, name)?;
-            if let Some(obj) = value.as_object() {
-                if obj.as_xml_object().is_some() || obj.as_xml_list_object().is_some() {
-                    return Err(format!(
-                        "Cannot set an XML/XMLList object {:?} as an attribute",
-                        obj
-                    )
-                    .into());
-                }
-            }
             let Some(local_name) = name.local_name() else {
                 return Err(format!("Cannot set attribute {:?} without a local name", name).into());
             };

tests/tests/swfs/avm2/xml_as_attribute/Test.as

@@ -0,0 +1,21 @@
+package
+{
+    import flash.display.Sprite;
+    public class Test extends Sprite
+    {
+    }
+}
+
+var main:XML = <root><item>A</item></root>;
+
+var part:XML = <hello><a>B</a><b>C</b></hello>;
+
+trace(main);
+
+main.item[0].@name = "Hello";
+
+trace(main);
+
+main.item[0].@name2 = part;
+
+trace(main);

tests/tests/swfs/avm2/xml_as_attribute/output.txt

@@ -0,0 +1,9 @@
+<root>
+  <item>A</item>
+</root>
+<root>
+  <item name="Hello">A</item>
+</root>
+<root>
+  <item name="Hello" name2="&lt;hello>&#xA;  &lt;a>B&lt;/a>&#xA;  &lt;b>C&lt;/b>&#xA;&lt;/hello>">A</item>
+</root>

tests/tests/swfs/avm2/xml_as_attribute/test.toml

@@ -0,0 +1 @@
+num_ticks = 1

tests/tests/swfs/avm2/xml_list_as_attribute/Test.as

@@ -0,0 +1,21 @@
+package
+{
+    import flash.display.Sprite;
+    public class Test extends Sprite
+    {
+    }
+}
+
+var main:XML = <root><item>A</item></root>;
+
+var part:XMLList = new XMLList("<root><item>A</item><item>B</item></root>");
+
+trace(main);
+
+main.item[0].@name = "Hello";
+
+trace(main);
+
+main.item[0].@name2 = part;
+
+trace(main);

tests/tests/swfs/avm2/xml_list_as_attribute/output.txt

@@ -0,0 +1,9 @@
+<root>
+  <item>A</item>
+</root>
+<root>
+  <item name="Hello">A</item>
+</root>
+<root>
+  <item name="Hello" name2="&lt;root>&#xA;  &lt;item>A&lt;/item>&#xA;  &lt;item>B&lt;/item>&#xA;&lt;/root>">A</item>
+</root>

tests/tests/swfs/avm2/xml_list_as_attribute/test.toml

@@ -0,0 +1 @@
+num_ticks = 1