Fix missing 'mut'.
@@ -167,7 +167,7 @@ impl<N: Real, T> NarrowPhase<N, T> for DefaultNarrowPhase<N> {
match (co1.query_type(), co2.query_type()) {
(GeometricQueryType::Contacts(..), GeometricQueryType::Contacts(..)) => {
- if let Some(detector) = self.contact_generators.remove(&key) {
+ if let Some(mut detector) = self.contact_generators.remove(&key) {
// Register a collision lost event if there was a contact.
if detector.num_contacts() != 0 {
contact_events.push(ContactEvent::Stopped(co1.handle(), co2.handle()));
