events: reset event state after dispatch

Fixes #54617

lib/internal/event_target.js

@@ -60,6 +60,7 @@ const kEvents = Symbol('kEvents');
 const kIsBeingDispatched = Symbol('kIsBeingDispatched');
 const kStop = Symbol('kStop');
 const kTarget = Symbol('kTarget');
+const kCurrentTarget = Symbol('kCurrentTarget');
 const kHandlers = Symbol('kHandlers');
 const kWeakHandler = Symbol('kWeak');
 const kResistStopPropagation = Symbol('kResistStopPropagation');
@@ -126,6 +127,7 @@ class Event {
     }
 
     this[kTarget] = null;
+    this[kCurrentTarget] = null;
     this[kIsBeingDispatched] = false;
   }
 
@@ -196,7 +198,7 @@ class Event {
   get currentTarget() {
     if (!isEvent(this))
       throw new ERR_INVALID_THIS('Event');
-    return this[kTarget];
+    return this[kCurrentTarget];
   }
 
   /**
@@ -757,20 +759,23 @@ class EventTarget {
     const createEvent = () => {
       if (event === undefined) {
         event = this[kCreateEvent](nodeValue, type);
-        event[kTarget] = this;
+        event[kCurrentTarget] = this;
         event[kIsBeingDispatched] = true;
       }
       return event;
     };
     if (event !== undefined) {
       event[kTarget] = this;
+      event[kCurrentTarget] = this;
       event[kIsBeingDispatched] = true;
     }
 
     const root = this[kEvents].get(type);
     if (root === undefined || root.next === undefined) {
-      if (event !== undefined)
+      if (event !== undefined) {
+        event[kCurrentTarget] = null;
         event[kIsBeingDispatched] = false;
+      }
       return true;
     }
 
@@ -827,8 +832,10 @@ class EventTarget {
       handler = next;
     }
 
-    if (event !== undefined)
+    if (event !== undefined) {
+      event[kCurrentTarget] = null;
       event[kIsBeingDispatched] = false;
+    }
   }
 
   [kCreateEvent](nodeValue, type) {

test/fixtures/wpt/README.md

@@ -14,7 +14,7 @@ Last update:
 - compression: https://github.com/web-platform-tests/wpt/tree/5aa50dd415/compression
 - console: https://github.com/web-platform-tests/wpt/tree/767ae35464/console
 - dom/abort: https://github.com/web-platform-tests/wpt/tree/d1f1ecbd52/dom/abort
-- dom/events: https://github.com/web-platform-tests/wpt/tree/ab8999891c/dom/events
+- dom/events: https://github.com/web-platform-tests/wpt/tree/0a811c5161/dom/events
 - encoding: https://github.com/web-platform-tests/wpt/tree/5aa50dd415/encoding
 - fetch/data-urls/resources: https://github.com/web-platform-tests/wpt/tree/7c79d998ff/fetch/data-urls/resources
 - FileAPI: https://github.com/web-platform-tests/wpt/tree/cceaf3628d/FileAPI

test/fixtures/wpt/dom/events/Event-dispatch-click.html

@@ -87,6 +87,22 @@
   child.dispatchEvent(new MouseEvent("click", {bubbles:true}))
 }, "pick the first with activation behavior <a href>")
 
+async_test(function(t) {
+  var input = document.createElement("input")
+  input.type = "radio"
+  dump.appendChild(input)
+  input.onclick = t.step_func(function() {
+    assert_false(input.checked, "input pre-click must not be triggered")
+  })
+  var child = input.appendChild(document.createElement("input"))
+  child.type = "radio"
+  child.onclick = t.step_func(function() {
+    assert_true(child.checked, "child pre-click must be triggered")
+  })
+  child.dispatchEvent(new MouseEvent("click", {bubbles:true}))
+  t.done()
+}, "pick the first with activation behavior <input type=radio>")
+
 async_test(function(t) {
   var input = document.createElement("input")
   input.type = "checkbox"
@@ -173,6 +189,46 @@
   t.done()
 }, "disabled checkbox still has activation behavior, part 2")
 
+async_test(function(t) {
+  var state = "start"
+
+  var form = document.createElement("form")
+  form.onsubmit = t.step_func(() => {
+    if(state == "start" || state == "radio") {
+      state = "failure"
+    } else if(state == "form") {
+      state = "done"
+    }
+    return false
+  })
+  dump.appendChild(form)
+  var button = form.appendChild(document.createElement("button"))
+  button.type = "submit"
+  var radio = button.appendChild(document.createElement("input"))
+  radio.type = "radio"
+  radio.onclick = t.step_func(() => {
+    if(state == "start") {
+      assert_unreached()
+    } else if(state == "radio") {
+      assert_true(radio.checked)
+    }
+  })
+  radio.disabled = true
+  radio.click()
+  assert_equals(state, "start")
+
+  state = "radio"
+  radio.disabled = false
+  radio.click()
+  assert_equals(state, "radio")
+
+  state = "form"
+  button.click()
+  assert_equals(state, "done")
+
+  t.done()
+}, "disabled radio still has activation behavior")
+
 async_test(function(t) {
   var input = document.createElement("input")
   input.type = "checkbox"

test/fixtures/wpt/dom/events/Event-dispatch-on-disabled-elements.html

@@ -19,7 +19,7 @@
 <body>
 <script>
 // HTML elements that can be disabled
-const formElements = ["button", "fieldset", "input", "select", "textarea"];
+const formElements = ["button", "input", "select", "textarea"];
 
 test(() => {
   for (const localName of formElements) {

test/fixtures/wpt/dom/events/EventTarget-constructible.any.js

@@ -23,6 +23,23 @@ test(() => {
   assert_equals(callCount, 2);
 }, "A constructed EventTarget can be used as expected");
 
+test(() => {
+  const target = new EventTarget();
+  const event = new Event("foo");
+
+  function listener(e) {
+    assert_equals(e, event);
+    assert_equals(e.target, target);
+    assert_equals(e.currentTarget, target);
+    assert_array_equals(e.composedPath(), [target]);
+  }
+  target.addEventListener("foo", listener, { once: true });
+  target.dispatchEvent(event);
+  assert_equals(event.target, target);
+  assert_equals(event.currentTarget, null);
+  assert_array_equals(event.composedPath(), []);
+}, "A constructed EventTarget implements dispatch correctly");
+
 test(() => {
   class NicerEventTarget extends EventTarget {
     on(...args) {

test/fixtures/wpt/dom/events/event-global.html

@@ -114,4 +114,14 @@
 
   target.dispatchEvent(new Event("click"));
 }, "window.event is set to the current event, which is the event passed to dispatch");
+
+async_test(t => {
+  let target = new XMLHttpRequest();
+
+  target.onload = t.step_func_done(e => {
+    assert_equals(e, window.event);
+  });
+
+  target.dispatchEvent(new Event("load"));
+}, "window.event is set to the current event, which is the event passed to dispatch (2)");
 </script>