tor-browser

commit 3a0b29121e2273701a63210a4dc075f1fa60c976
parent e821559f74fdbcff1b9d7434ade855a5991ec25b
Author: Alice Boxhall <95208+alice@users.noreply.github.com>
Date:   Tue,  6 Jan 2026 16:13:54 +0000

Bug 1989323 - Make `referenceTarget` IDL attributes on ShadowRoot, HTMLTemplateElement and ShadowRootInit nullable. r=dom-core,webidl,saschanaz,smaug

This was resolved in https://github.com/WICG/webcomponents/issues/1093.

Differential Revision: https://phabricator.services.mozilla.com/D265456

Diffstat:
M
dom/base/Element.h
 | 
2
+-
M
dom/base/ShadowRoot.cpp
 | 
4
+---
M
dom/base/ShadowRoot.h
 | 
10
++++++++--
M
dom/webidl/Element.webidl
 | 
2
+-
M
dom/webidl/HTMLTemplateElement.webidl
 | 
2
+-
M
dom/webidl/ShadowRoot.webidl
 | 
2
+-
D
testing/web-platform/meta/shadow-dom/reference-target/tentative/reference-target-basics.html.ini
 | 
6
------

7 files changed, 13 insertions(+), 15 deletions(-)
diff --git a/dom/base/Element.h b/dom/base/Element.h
@@ -1511,7 +1511,7 @@ class Element : public FragmentOrElement {
       SlotAssignmentMode aSlotAssignmentMode = SlotAssignmentMode::Named,
       ShadowRootClonable aClonable = ShadowRootClonable::No,
       ShadowRootSerializable aSerializable = ShadowRootSerializable::No,
-      const nsAString& aReferenceTarget = EmptyString());
+      const nsAString& aReferenceTarget = VoidString());
 
   // Attach UA Shadow Root if it is not attached.
   enum class NotifyUAWidgetSetup : bool { No, Yes };
diff --git a/dom/base/ShadowRoot.cpp b/dom/base/ShadowRoot.cpp
@@ -71,8 +71,7 @@ ShadowRoot::ShadowRoot(Element* aElement, ShadowRootMode aMode,
       mIsAvailableToElementInternals(false),
       mIsDeclarative(aDeclarative),
       mIsClonable(aIsClonable),
-      mIsSerializable(aIsSerializable),
-      mReferenceTarget(nsGkAtoms::_empty) {
+      mIsSerializable(aIsSerializable) {
   // nsINode.h relies on this.
   MOZ_ASSERT(static_cast<nsINode*>(this) == reinterpret_cast<nsINode*>(this));
   MOZ_ASSERT(static_cast<nsIContent*>(this) ==
@@ -941,6 +940,5 @@ void ShadowRoot::GetHTML(const GetHTMLOptions& aOptions, nsAString& aResult) {
       aOptions.mShadowRoots);
 }
 void ShadowRoot::SetReferenceTarget(RefPtr<nsAtom> aTarget) {
-  MOZ_ASSERT(aTarget);
   mReferenceTarget = std::move(aTarget);
 }
diff --git a/dom/base/ShadowRoot.h b/dom/base/ShadowRoot.h
@@ -276,16 +276,22 @@ class ShadowRoot final : public DocumentFragment, public DocumentOrShadowRoot {
   void GetHTML(const GetHTMLOptions& aOptions, nsAString& aResult);
 
   void GetReferenceTarget(nsAString& aResult) const {
+    if (!mReferenceTarget) {
+      aResult.SetIsVoid(true);
+      return;
+    }
     mReferenceTarget->ToString(aResult);
   }
   nsAtom* ReferenceTarget() const { return mReferenceTarget; }
   void SetReferenceTarget(const nsAString& aValue) {
+    if (aValue.IsVoid()) {
+      return SetReferenceTarget(nullptr);
+    }
     SetReferenceTarget(NS_Atomize(aValue));
   }
   void SetReferenceTarget(RefPtr<nsAtom> aTarget);
   Element* GetReferenceTargetElement() const {
-    return mReferenceTarget->IsEmpty() ? nullptr
-                                       : GetElementById(mReferenceTarget);
+    return mReferenceTarget ? GetElementById(mReferenceTarget) : nullptr;
   }
 
  protected:
diff --git a/dom/webidl/Element.webidl b/dom/webidl/Element.webidl
@@ -282,7 +282,7 @@ dictionary ShadowRootInit {
 
   // https://github.com/whatwg/dom/pull/1353
   [Pref="dom.shadowdom.referenceTarget.enabled"]
-  DOMString referenceTarget;
+  DOMString? referenceTarget;
 };
 
 // https://dom.spec.whatwg.org/#element
diff --git a/dom/webidl/HTMLTemplateElement.webidl b/dom/webidl/HTMLTemplateElement.webidl
@@ -23,5 +23,5 @@ interface HTMLTemplateElement : HTMLElement {
   [CEReactions, SetterThrows]
   attribute boolean shadowRootSerializable;
   [CEReactions, SetterThrows, Pref="dom.shadowdom.referenceTarget.enabled"]
-  attribute DOMString shadowRootReferenceTarget;
+  attribute DOMString? shadowRootReferenceTarget;
 };
diff --git a/dom/webidl/ShadowRoot.webidl b/dom/webidl/ShadowRoot.webidl
@@ -32,7 +32,7 @@ interface ShadowRoot : DocumentFragment
   attribute EventHandler onslotchange;
 
   [Pref="dom.shadowdom.referenceTarget.enabled"]
-  attribute DOMString referenceTarget;
+  attribute DOMString? referenceTarget;
 
   Element? getElementById(DOMString elementId);
 
diff --git a/testing/web-platform/meta/shadow-dom/reference-target/tentative/reference-target-basics.html.ini b/testing/web-platform/meta/shadow-dom/reference-target/tentative/reference-target-basics.html.ini
@@ -1,6 +0,0 @@
-[reference-target-basics.html]
-  [ShadowRoot.referenceTarget defaults to null when shadow is created declaratively]
-    expected: FAIL
-
-  [ShadowRoot.referenceTarget defaults to null when shadow is created imperatively]
-    expected: FAIL