Bug 1520869 - Allow input/change events on disabled radio/checkboxes r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D102517

dom/html/nsGenericHTMLElement.cpp

@@ -2071,6 +2071,7 @@ bool nsGenericHTMLFormElement::IsElementDisabledForEvents(WidgetEvent* aEvent,
     case eAnimationEnd:
     case eAnimationIteration:
     case eAnimationCancel:
+    case eFormChange:
     case eMouseMove:
     case eMouseOver:
     case eMouseOut:
@@ -2093,6 +2094,10 @@ bool nsGenericHTMLFormElement::IsElementDisabledForEvents(WidgetEvent* aEvent,
       break;
   }
 
+  if (aEvent->mSpecifiedEventType == nsGkAtoms::oninput) {
+    return false;
+  }
+
   // FIXME(emilio): This poking at the style of the frame is slightly bogus
   // unless we flush before every event, which we don't really want to do.
   if (aFrame && aFrame->StyleUI()->mUserInput == StyleUserInput::None) {

testing/web-platform/tests/dom/events/Event-dispatch-click.html

@@ -289,6 +289,23 @@ test(t => {
   assert_false(input.checked);
 }, `disabled radio should get legacy-canceled-activation behavior 2`);
 
+for (const type of ["checkbox", "radio"]) {
+  for (const handler of ["oninput", "onchange"]) {
+    async_test(t => {
+      const input = document.createElement("input");
+      input.type = type;
+      input.onclick = t.step_func(ev => {
+        input.disabled = true;
+      });
+      input[handler] = t.step_func(ev => {
+        assert_equals(input.checked, true);
+        t.done();
+      });
+      input.click();
+    }, `disabling ${type} in onclick listener shouldn't suppress ${handler}`);
+  }
+}
+
 async_test(function(t) {
   var form = document.createElement("form")
   var didSubmit = false