Enter realms more consistently during the script event loop.

1 files changed, 7 insertions, 1 deletions

diff --git a/components/script/microtask.rs b/components/script/microtask.rs
index b97368fcad5..10322bb2fef 100644
--- a/components/script/microtask.rs
+++ b/components/script/microtask.rs
@@ -15,9 +15,10 @@ use crate::dom::globalscope::GlobalScope;
 use crate::dom::htmlimageelement::ImageElementMicrotask;
 use crate::dom::htmlmediaelement::MediaElementMicrotask;
 use crate::dom::mutationobserver::MutationObserver;
+use crate::realms::enter_realm;
 use crate::script_runtime::{notify_about_rejected_promises, JSContext};
 use crate::script_thread::ScriptThread;
-use js::jsapi::{JobQueueIsEmpty, JobQueueMayNotBeEmpty};
+use js::jsapi::{JSAutoRealm, JobQueueIsEmpty, JobQueueMayNotBeEmpty};
 use msg::constellation_msg::PipelineId;
 use std::cell::Cell;
 use std::mem;
@@ -44,6 +45,7 @@ pub enum Microtask {
 
 pub trait MicrotaskRunnable {
     fn handler(&self) {}
+    fn enter_realm(&self) -> JSAutoRealm;
 }
 
 /// A promise callback scheduled to run during the next microtask checkpoint (#4283).
@@ -108,19 +110,23 @@ impl MicrotaskQueue {
                         if let Some(target) = target_provider(job.pipeline) {
                             let was_interacting = ScriptThread::is_user_interacting();
                             ScriptThread::set_user_interacting(job.is_user_interacting);
+                            let _realm = enter_realm(&*target);
                             let _ = job.callback.Call_(&*target, ExceptionHandling::Report);
                             ScriptThread::set_user_interacting(was_interacting);
                         }
                     },
                     Microtask::User(ref job) => {
                         if let Some(target) = target_provider(job.pipeline) {
+                            let _realm = enter_realm(&*target);
                             let _ = job.callback.Call_(&*target, ExceptionHandling::Report);
                         }
                     },
                     Microtask::MediaElement(ref task) => {
+                        let _realm = task.enter_realm();
                         task.handler();
                     },
                     Microtask::ImageElement(ref task) => {
+                        let _realm = task.enter_realm();
                         task.handler();
                     },
                     Microtask::CustomElementReaction => {