Bug 1835464 - Check dialog is modal flag instead of open attribute in 'check popover validity' algorithm. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D181089

dom/html/HTMLDialogElement.cpp

@@ -78,11 +78,6 @@ void HTMLDialogElement::Show(ErrorResult& aError) {
         "Cannot call show() on an open modal dialog.");
   }
 
-  if (IsPopoverOpen()) {
-    return aError.ThrowInvalidStateError(
-        "Dialog element is already an open popover.");
-  }
-
   SetOpen(true, IgnoreErrors());
 
   StorePreviouslyFocusedElement();

dom/html/nsGenericHTMLElement.cpp

@@ -3276,10 +3276,12 @@ bool nsGenericHTMLElement::CheckPopoverValidity(
     return false;
   }
 
-  if (IsHTMLElement(nsGkAtoms::dialog) && HasAttr(nsGkAtoms::open)) {
+  if (auto* dialog = HTMLDialogElement::FromNode(this)) {
-    aRv.ThrowInvalidStateError("Element is an open <dialog> element");
+    if (dialog->IsInTopLayer()) {
+      aRv.ThrowInvalidStateError("Element is a modal <dialog> element");
       return false;
     }
+  }
 
   if (State().HasState(ElementState::FULLSCREEN)) {
     aRv.ThrowInvalidStateError("Element is fullscreen");

testing/web-platform/meta/html/semantics/popovers/popover-top-layer-combinations.html.ini

@@ -1,16 +1,4 @@
 [popover-top-layer-combinations.html]
-  [Popover combination: Popover Dialog]
-    expected: FAIL
-
-  [Popover combination: Open Non-modal Popover Dialog]
-    expected: FAIL
-
   [Popover combination: Fullscreen Popover]
     expected:
       if os == "linux": FAIL
-
-  [Popover combination: Fullscreen Popover Dialog]
-    expected: FAIL
-
-  [Popover combination: Fullscreen Open Non-modal Popover Dialog]
-    expected: FAIL