Don't reset exception handle after calling ErrWithV8Handle::get_handl…

…e() (denoland#4214)

core/es_isolate.rs

@@ -315,19 +315,14 @@ impl EsIsolate {
  let mut resolver = resolver_handle.get(scope).unwrap();
  resolver_handle.reset(scope);
 
- let exception = match ErrBox::downcast::<ErrWithV8Handle>(err) {
- Ok(mut err) => {
- let handle = err.get_handle();
- let exception = handle.get(scope).unwrap();
- handle.reset(scope);
- exception
- }
- Err(err) => {
+ let exception = err
+ .downcast_ref::<ErrWithV8Handle>()
+ .and_then(|err| err.get_handle().get(scope))
+ .unwrap_or_else(|| {
  let message = err.to_string();
  let message = v8::String::new(scope, &message).unwrap();
  v8::Exception::type_error(scope, message)
- }
- };
+ });
 
  resolver.reject(context, exception).unwrap();
  scope.isolate().run_microtasks();

core/isolate.rs

@@ -1164,8 +1164,8 @@ impl ErrWithV8Handle {
  Self { err, handle }
  }
 
- pub fn get_handle(&mut self) -> &mut v8::Global<v8::Value> {
- &mut self.handle
+ pub fn get_handle(&self) -> &v8::Global<v8::Value> {
+ &self.handle
  }
 }