Don't recurse in Node::GetRootNode (#35725)

* Don't recurse in Node::GetRootNode

This causes servo to crash when computing
the root of deeply nested shadow roots.

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

* Add test case

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

---------

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

components/script/dom/node.rs

@@ -2887,19 +2887,16 @@ impl NodeMethods<crate::DomTypeHolder> for Node {
 
     /// <https://dom.spec.whatwg.org/#dom-node-getrootnode>
     fn GetRootNode(&self, options: &GetRootNodeOptions) -> DomRoot<Node> {
+        if !options.composed {
             if let Some(shadow_root) = self.containing_shadow_root() {
-            return if options.composed {
-                // shadow-including root.
-                shadow_root.Host().upcast::<Node>().GetRootNode(options)
-            } else {
-                DomRoot::from_ref(shadow_root.upcast::<Node>())
-            };
+                return DomRoot::upcast(shadow_root);
+            }
         }
 
-        if self.is_in_a_document_tree() {
+        if self.is_connected() {
             DomRoot::from_ref(self.owner_doc().upcast::<Node>())
         } else {
-            self.inclusive_ancestors(ShadowIncluding::No)
+            self.inclusive_ancestors(ShadowIncluding::Yes)
                 .last()
                 .unwrap()
         }

tests/wpt/mozilla/meta/MANIFEST.json

@@ -13496,14 +13496,14 @@
      ]
     ],
     "interfaces.https.html": [
-     "6c48986beea5c8aca4e54c6da0fb8f3b7a4390e0",
+     "81f4d942f94366d8f9ecf22cfc3e1e22fe4ab8f1",
      [
       null,
       {}
      ]
     ],
     "interfaces.worker.js": [
-     "4ac5c822dcc6fbb021050ac2ab2ba4d04452d945",
+     "06eb8d3ba2334951cb1e0f791527ba118d4f13ec",
      [
       "mozilla/interfaces.worker.html",
       {}
@@ -14337,6 +14337,15 @@
      ]
     ]
    },
+   "shadow-dom": {
+    "getrootnode-in-deeply-nested-shadow.html": [
+     "355cc270e6020f40176afac26c49a14a59b67169",
+     [
+      null,
+      {}
+     ]
+    ]
+   },
    "webxr": {
     "create_session.https.html": [
      "5b5d485b372bfffb22204bc162c9e182306395cb",

tests/wpt/mozilla/meta/__dir__.ini

@@ -0,0 +1 @@
+prefs: ["dom_imagebitmap_enabled:true", "dom_offscreen_canvas_enabled:true", "dom_shadowdom_enabled:true", "dom_xpath_enabled:true", "dom_intersection_observer_enabled:true", "dom_resize_observer_enabled:true", "dom_notification_enabled:true", "dom_fontface_enabled:true"]

tests/wpt/mozilla/meta/mozilla/partial_shadow_dom_layout_style.html.ini

@@ -1,2 +0,0 @@
-[partial_shadow_dom_layout_style.html]
-  expected: FAIL

tests/wpt/mozilla/tests/mozilla/interfaces.https.html

@@ -92,6 +92,7 @@ test_interfaces([
   "FileList",
   "FileReader",
   "FocusEvent",
+  "FontFace",
   "FontFaceSet",
   "FormData",
   "FormDataEvent",
@@ -181,7 +182,10 @@ test_interfaces([
   "IIRFilterNode",
   "ImageData",
   "Image",
+  "ImageBitmap",
   "InputEvent",
+  "IntersectionObserver",
+  "IntersectionObserverEntry",
   "KeyboardEvent",
   "Location",
   "MediaElementAudioSourceNode",
@@ -213,6 +217,8 @@ test_interfaces([
   "Notification",
   "OfflineAudioCompletionEvent",
   "OfflineAudioContext",
+  "OffscreenCanvas",
+  "OffscreenCanvasRenderingContext2D",
   "Option",
   "OscillatorNode",
   "PageTransitionEvent",
@@ -242,6 +248,9 @@ test_interfaces([
   "ReadableByteStreamController",
   "ReadableStreamBYOBRequest",
   "Request",
+  "ResizeObserver",
+  "ResizeObserverEntry",
+  "ResizeObserverSize",
   "Response",
   "Screen",
   "SecurityPolicyViolationEvent",
@@ -303,6 +312,9 @@ test_interfaces([
   "XMLHttpRequestEventTarget",
   "XMLHttpRequestUpload",
   "XMLSerializer",
+  "XPathEvaluator",
+  "XPathExpression",
+  "XPathResult",
   "XRBoundedReferenceSpace",
   "XRFrame",
   "XRHand",

tests/wpt/mozilla/tests/mozilla/interfaces.worker.js

@@ -37,11 +37,14 @@ test_interfaces([
   "FormData",
   "Headers",
   "History",
+  "ImageBitmap",
   "ImageData",
   "MessageChannel",
   "MessageEvent",
   "MessagePort",
   "Notification",
+  "OffscreenCanvas",
+  "OffscreenCanvasRenderingContext2D",
   "Performance",
   "PerformanceEntry",
   "PerformanceMark",

tests/wpt/mozilla/tests/shadow-dom/getrootnode-in-deeply-nested-shadow.html

@@ -0,0 +1,26 @@
+<!--https://github.com/servo/servo/issues/35724 -->
+<html>
+    <head>
+        <script src="/resources/testharness.js"></script>
+        <script src="/resources/testharnessreport.js"></script>
+    </head>
+<body>
+    <script>
+        'use strict';
+        test(() => {
+            let original_host = document.createElement("div");
+            original_host.id = "original-host";
+            let current_host = original_host;
+            for (let i = 0; i < 10000; i++) {
+                let root = current_host.attachShadow({ mode: "open" });
+                let new_host = document.createElement("div");
+                root.appendChild(new_host);
+                current_host = new_host;
+            }
+
+            let root_of_tree = current_host.getRootNode({ composed: true });
+            assert_equals(root_of_tree.id, "original-host");
+        }, "Calling Node.getRootNode in a deeply nested shadow tree must return the correct result without crashing");
+    </script>
+</body>
+</html>