1 files changed, 17 insertions, 3 deletions
diff --git a/components/script/dom/webxr/xrhand.rs b/components/script/dom/webxr/xrhand.rs
index a9253ccb72b..b466cf32086 100644
--- a/components/script/dom/webxr/xrhand.rs
+++ b/components/script/dom/webxr/xrhand.rs
@@ -3,9 +3,12 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use dom_struct::dom_struct;
+use js::jsapi::JSContext;
+use js::rust::MutableHandleValue;
 use webxr_api::{FingerJoint, Hand, Joint};
 
 use crate::dom::bindings::codegen::Bindings::XRHandBinding::{XRHandJoint, XRHandMethods};
+use crate::dom::bindings::conversions::ToJSValConvertible;
 use crate::dom::bindings::iterable::Iterable;
 use crate::dom::bindings::reflector::{reflect_dom_object, Reflector};
 use crate::dom::bindings::root::{Dom, DomRoot};
@@ -163,19 +166,30 @@ impl XRHandMethods<crate::DomTypeHolder> for XRHand {
     }
 }
 
+/// A wrapper to work around a crown error—Root<T> has a crown annotation on it that is not present
+/// on the Iterable::Value associated type. The absence is harmless in this case.
+pub(crate) struct ValueWrapper(pub DomRoot<XRJointSpace>);
+
+impl ToJSValConvertible for ValueWrapper {
+    #[allow(unsafe_code)]
+    unsafe fn to_jsval(&self, cx: *mut JSContext, rval: MutableHandleValue) {
+        self.0.to_jsval(cx, rval)
+    }
+}
+
 impl Iterable for XRHand {
     type Key = XRHandJoint;
-    type Value = DomRoot<XRJointSpace>;
+    type Value = ValueWrapper;
 
     fn get_iterable_length(&self) -> u32 {
         JOINT_SPACE_MAP.len() as u32
     }
 
-    fn get_value_at_index(&self, n: u32) -> DomRoot<XRJointSpace> {
+    fn get_value_at_index(&self, n: u32) -> ValueWrapper {
         let joint = JOINT_SPACE_MAP[n as usize].1;
         self.spaces
             .get(joint)
-            .map(|j| DomRoot::from_ref(&**j))
+            .map(|j| ValueWrapper(DomRoot::from_ref(&**j)))
             .expect("Failed to get joint pose")
     }