avm2: Implement XML.setChildren

core/src/avm2/globals/XML.as

@@ -87,6 +87,7 @@ package {
         AS3 native function insertChildBefore(child1:Object, child2:Object):*;
         // NOTE: Docs lie, value can be anything not just XML.
         AS3 native function replace(propertyName:Object, value:*):XML;
+        AS3 native function setChildren(value:Object):XML;
 
         AS3 function valueOf():XML {
             return this;
@@ -252,6 +253,11 @@ package {
             return self.AS3::replace(propertyName, value);
         }
 
+        prototype.setChildren = function(value:Object):XML {
+            var self:XML = this;
+            return self.AS3::setChildren(value);
+        }
+
         public static const length:int = 1;
     }
 }

core/src/avm2/globals/xml.rs

@@ -745,6 +745,22 @@ pub fn replace<'gc>(
     Ok(xml.into())
 }
 
+// ECMA-357 13.4.4.33 XML.prototype.setChildren (value)
+pub fn set_children<'gc>(
+    activation: &mut Activation<'_, 'gc>,
+    this: Object<'gc>,
+    args: &[Value<'gc>],
+) -> Result<Value<'gc>, Error<'gc>> {
+    let xml = this.as_xml_object().unwrap();
+    let value = args.get_value(0);
+
+    // 1. Call the [[Put]] method of x with arguments "*" and value
+    xml.set_property_local(&Multiname::any(activation.gc()), value, activation)?;
+
+    // 2. Return x
+    Ok(xml.into())
+}
+
 pub fn set_notification<'gc>(
     activation: &mut Activation<'_, 'gc>,
     this: Object<'gc>,

tests/tests/swfs/from_avmplus/e4x/XML/e13_4_4_33/test.toml

@@ -1,2 +1 @@
 num_ticks = 1
-known_failure = true