always encode has_default in objdestruct/arraydestruct

crates/dash_compiler/src/lib.rs

@@ -1147,6 +1147,7 @@ impl<'interner> Visitor<Result<(), Error>> for FunctionCompiler<'interner> {
                                     .cp
                                     .add_symbol(name)
                                     .map_err(|_| Error::ConstantPoolLimitExceeded(span))?;
+                                ib.write_bool(false); // Defaults are unsupported
                                 ib.writew(var_id);
                                 ib.writew(ident_id);
                             }
@@ -1179,6 +1180,8 @@ impl<'interner> Visitor<Result<(), Error>> for FunctionCompiler<'interner> {
                                             .cp
                                             .add_number(local as f64)
                                             .map_err(|_| Error::ConstantPoolLimitExceeded(span))?;
+
+                                        ib.write_bool(false); // Defaults are unsupported
                                         ib.writew(var_id);
                                     }
                                     ArrayMemberKind::Spread(_) => unimplementedc!(span, "rest operator in array destructuring is unsupported"),

crates/dash_vm/src/dispatch.rs

@@ -2089,15 +2089,15 @@ mod handlers {
                 idents.push(ident);
             }
 
-            let mut prop = obj.get_property(&mut cx, ident.into())?;
+            let mut prop = obj.get_property(&mut cx, ident.into())?.root(&mut cx.scope);
             if has_default {
                 // NB: we need to at least pop it from the stack even if the property exists
-                let default = cx.pop_stack();
-                if prop.is_undefined() {
+                let default = cx.pop_stack_rooted();
+                if matches!(prop.unpack(), ValueKind::Undefined(_)) {
                     prop = default;
                 }
             }
-            cx.set_local(id as usize, prop);
+            cx.set_local(id as usize, prop.into());
         }
 
         if let Some(rest_id) = rest_id {
@@ -2132,16 +2132,16 @@ mod handlers {
             if let Some((has_default, NumberWConstant(id))) = id {
                 let id = id as usize;
                 let key = cx.scope.intern_usize(i);
-                let mut prop = array.get_property(&mut cx.scope, key.into())?;
+                let mut prop = array.get_property(&mut cx.scope, key.into())?.root(&mut cx.scope);
 
                 if has_default {
                     // NB: we need to at least pop it from the stack even if the property exists
-                    let default = cx.pop_stack();
-                    if prop.is_undefined() {
+                    let default = cx.pop_stack_rooted();
+                    if matches!(prop.unpack(), ValueKind::Undefined(_)) {
                         prop = default;
                     }
                 }
-                cx.set_local(id, prop);
+                cx.set_local(id, prop.into());
             }
         }
 

crates/dash_vm/src/value/mod.rs

@@ -380,12 +380,6 @@ impl Unrooted {
         Self { value }
     }
 
-    /// Checks if this value is undefined.
-    /// As this does not require access to any garbage collected resources, this operation is safe without rooting.
-    pub fn is_undefined(self) -> bool {
-        matches!(self.value.unpack(), ValueKind::Undefined(_))
-    }
-
     /// Returns an unprotected, unrooted reference to the value.
     ///
     /// # Safety