avm1: Fix `this` inside watchers (#5276)

* fix: fix 'this' inside watchers

* tests: test value of 'this' in watcher

* lint: cargo fmt

core/src/avm1/function.rs

@@ -724,8 +724,9 @@ impl<'gc> TObject<'gc> for FunctionObject<'gc> {
         activation: &mut Activation<'_, 'gc, '_>,
         name: &str,
         value: &mut Value<'gc>,
+        this: Object<'gc>,
     ) -> Result<(), Error<'gc>> {
-        self.base.call_watcher(activation, name, value)
+        self.base.call_watcher(activation, name, value, this)
     }
 
     fn watch(

core/src/avm1/object.rs

@@ -161,9 +161,9 @@ pub trait TObject<'gc>: 'gc + Collect + Debug + Into<Object<'gc>> + Clone + Copy
         }
 
         let mut value = value;
-        let watcher_result = self.call_watcher(activation, name, &mut value);
-
         let this = (*self).into();
+        let watcher_result = self.call_watcher(activation, name, &mut value, this);
+
         if !self.has_own_property(activation, name) {
             // Before actually inserting a new property, we need to crawl the
             // prototype chain for virtual setters.
@@ -360,6 +360,7 @@ pub trait TObject<'gc>: 'gc + Collect + Debug + Into<Object<'gc>> + Clone + Copy
         activation: &mut Activation<'_, 'gc, '_>,
         name: &str,
         value: &mut Value<'gc>,
+        this: Object<'gc>,
     ) -> Result<(), Error<'gc>>;
 
     /// Set the 'watcher' of a given property.

core/src/avm1/object/array_object.rs

@@ -186,8 +186,9 @@ impl<'gc> TObject<'gc> for ArrayObject<'gc> {
         activation: &mut Activation<'_, 'gc, '_>,
         name: &str,
         value: &mut Value<'gc>,
+        this: Object<'gc>,
     ) -> Result<(), Error<'gc>> {
-        self.0.read().call_watcher(activation, name, value)
+        self.0.read().call_watcher(activation, name, value, this)
     }
 
     fn watch(

core/src/avm1/object/custom_object.rs

@@ -254,8 +254,9 @@ macro_rules! impl_custom_object {
             activation: &mut crate::avm1::Activation<'_, 'gc, '_>,
             name: &str,
             value: &mut crate::avm1::Value<'gc>,
+            this: crate::avm1::object::Object<'gc>,
         ) -> Result<(), crate::avm1::Error<'gc>> {
-            self.0.read().$field.call_watcher(activation, name, value)
+            self.0.read().$field.call_watcher(activation, name, value, this)
         }
 
         fn watch(

core/src/avm1/object/script_object.rs

@@ -319,6 +319,7 @@ impl<'gc> TObject<'gc> for ScriptObject<'gc> {
         activation: &mut Activation<'_, 'gc, '_>,
         name: &str,
         value: &mut Value<'gc>,
+        this: Object<'gc>,
     ) -> Result<(), Error<'gc>> {
         let mut result = Ok(());
         let watcher = self
@@ -329,7 +330,6 @@ impl<'gc> TObject<'gc> for ScriptObject<'gc> {
             .cloned();
         if let Some(watcher) = watcher {
             let old_value = self.get_stored(name, activation)?;
-            let this = (*self).into();
             match watcher.call(activation, name, old_value, *value, this, Some(this)) {
                 Ok(v) => *value = v,
                 Err(Error::ThrownValue(e)) => {

core/src/avm1/object/stage_object.rs

@@ -333,8 +333,12 @@ impl<'gc> TObject<'gc> for StageObject<'gc> {
         activation: &mut Activation<'_, 'gc, '_>,
         name: &str,
         value: &mut Value<'gc>,
+        this: Object<'gc>,
     ) -> Result<(), Error<'gc>> {
-        self.0.read().base.call_watcher(activation, name, value)
+        self.0
+            .read()
+            .base
+            .call_watcher(activation, name, value, this)
     }
 
     fn watch(

core/src/avm1/object/super_object.rs

@@ -181,8 +181,12 @@ impl<'gc> TObject<'gc> for SuperObject<'gc> {
         activation: &mut Activation<'_, 'gc, '_>,
         name: &str,
         value: &mut Value<'gc>,
+        this: Object<'gc>,
     ) -> Result<(), Error<'gc>> {
-        self.0.read().this.call_watcher(activation, name, value)
+        self.0
+            .read()
+            .this
+            .call_watcher(activation, name, value, this)
     }
 
     fn watch(

core/src/avm1/object/xml_attributes_object.rs

@@ -146,8 +146,9 @@ impl<'gc> TObject<'gc> for XmlAttributesObject<'gc> {
         activation: &mut Activation<'_, 'gc, '_>,
         name: &str,
         value: &mut Value<'gc>,
+        this: Object<'gc>,
     ) -> Result<(), Error<'gc>> {
-        self.base().call_watcher(activation, name, value)
+        self.base().call_watcher(activation, name, value, this)
     }
 
     fn watch(

core/src/avm1/object/xml_idmap_object.rs

@@ -148,8 +148,9 @@ impl<'gc> TObject<'gc> for XmlIdMapObject<'gc> {
         activation: &mut Activation<'_, 'gc, '_>,
         name: &str,
         value: &mut Value<'gc>,
+        this: Object<'gc>,
     ) -> Result<(), Error<'gc>> {
-        self.base().call_watcher(activation, name, value)
+        self.base().call_watcher(activation, name, value, this)
     }
 
     fn watch(

tests/tests/swfs/avm1/watch_textfield/output.txt

@@ -8,3 +8,5 @@ oldVal
 undefined
 newVal
 hello
+this
+_level0.text_field