Bug 1213818 - Align document.title for SVG documents with HTML spec; r=bz

This allows setting, and for getting, pays attention to only children of
the root element (instead of all descendants as in HTML).

dom/base/nsDocument.cpp

@@ -7014,8 +7014,8 @@ nsIDocument::GetHtmlChildElement(nsIAtom* aTag)
   return nullptr;
 }
 
-nsIContent*
-nsDocument::GetTitleContent(uint32_t aNamespace)
+Element*
+nsDocument::GetTitleElement()
 {
   // mMayHaveTitleElement will have been set to true if any HTML or SVG
   // <title> element has been bound to this document. So if it's false,
@@ -7025,19 +7025,26 @@ nsDocument::GetTitleContent(uint32_t aNamespace)
   if (!mMayHaveTitleElement)
     return nullptr;
 
+  Element* root = GetRootElement();
+  if (root && root->IsSVGElement(nsGkAtoms::svg)) {
+    // In SVG, the document's title must be a child
+    for (nsIContent* child = root->GetFirstChild();
+         child; child = child->GetNextSibling()) {
+      if (child->IsSVGElement(nsGkAtoms::title)) {
+        return child->AsElement();
+      }
+    }
+    return nullptr;
+  }
+
+  // We check the HTML namespace even for non-HTML documents, except SVG.  This
+  // matches the spec and the behavior of all tested browsers.
   nsRefPtr<nsContentList> list =
-    NS_GetContentList(this, aNamespace, NS_LITERAL_STRING("title"));
+    NS_GetContentList(this, kNameSpaceID_XHTML, NS_LITERAL_STRING("title"));
 
-  return list->Item(0, false);
-}
+  nsIContent* first = list->Item(0, false);
 
-void
-nsDocument::GetTitleFromElement(uint32_t aNamespace, nsAString& aTitle)
-{
-  nsIContent* title = GetTitleContent(aNamespace);
-  if (!title)
-    return;
-  nsContentUtils::GetNodeTextContent(title, false, aTitle);
+  return first ? first->AsElement() : nullptr;
 }
 
 NS_IMETHODIMP
@@ -7054,26 +7061,24 @@ nsDocument::GetTitle(nsString& aTitle)
 {
   aTitle.Truncate();
 
-  nsIContent *rootElement = GetRootElement();
-  if (!rootElement)
+  Element* rootElement = GetRootElement();
+  if (!rootElement) {
     return;
+  }
 
   nsAutoString tmp;
 
-  switch (rootElement->GetNameSpaceID()) {
 #ifdef MOZ_XUL
-    case kNameSpaceID_XUL:
-      rootElement->GetAttr(kNameSpaceID_None, nsGkAtoms::title, tmp);
-      break;
+  if (rootElement->IsXULElement()) {
+    rootElement->GetAttr(kNameSpaceID_None, nsGkAtoms::title, tmp);
+  } else
 #endif
-    case kNameSpaceID_SVG:
-      if (rootElement->IsSVGElement(nsGkAtoms::svg)) {
-        GetTitleFromElement(kNameSpaceID_SVG, tmp);
-        break;
-      } // else fall through
-    default:
-      GetTitleFromElement(kNameSpaceID_XHTML, tmp);
-      break;
+  {
+    Element* title = GetTitleElement();
+    if (!title) {
+      return;
+    }
+    nsContentUtils::GetNodeTextContent(title, false, tmp);
   }
 
   tmp.CompressWhitespace();
@@ -7083,41 +7088,56 @@ nsDocument::GetTitle(nsString& aTitle)
 NS_IMETHODIMP
 nsDocument::SetTitle(const nsAString& aTitle)
 {
-  Element *rootElement = GetRootElement();
-  if (!rootElement)
+  Element* rootElement = GetRootElement();
+  if (!rootElement) {
     return NS_OK;
-
-  switch (rootElement->GetNameSpaceID()) {
-    case kNameSpaceID_SVG:
-      return NS_OK; // SVG doesn't support setting a title
-#ifdef MOZ_XUL
-    case kNameSpaceID_XUL:
-      return rootElement->SetAttr(kNameSpaceID_None, nsGkAtoms::title,
-                                  aTitle, true);
-#endif
   }
 
+#ifdef MOZ_XUL
+  if (rootElement->IsXULElement()) {
+    return rootElement->SetAttr(kNameSpaceID_None, nsGkAtoms::title,
+                                aTitle, true);
+  }
+#endif
+
   // Batch updates so that mutation events don't change "the title
   // element" under us
   mozAutoDocUpdate updateBatch(this, UPDATE_CONTENT_MODEL, true);
 
-  nsIContent* title = GetTitleContent(kNameSpaceID_XHTML);
-  if (!title) {
-    Element *head = GetHeadElement();
-    if (!head)
-      return NS_OK;
+  nsCOMPtr<Element> title = GetTitleElement();
+  if (rootElement->IsSVGElement(nsGkAtoms::svg)) {
+    if (!title) {
+      nsRefPtr<mozilla::dom::NodeInfo> titleInfo =
+        mNodeInfoManager->GetNodeInfo(nsGkAtoms::title, nullptr,
+                                      kNameSpaceID_SVG,
+                                      nsIDOMNode::ELEMENT_NODE);
+      NS_NewSVGElement(getter_AddRefs(title), titleInfo.forget(),
+                       NOT_FROM_PARSER);
+      if (!title) {
+        return NS_OK;
+      }
+      rootElement->InsertChildAt(title, 0, true);
+    }
+  } else if (rootElement->IsHTMLElement()) {
+    if (!title) {
+      Element* head = GetHeadElement();
+      if (!head) {
+        return NS_OK;
+      }
 
-    {
       nsRefPtr<mozilla::dom::NodeInfo> titleInfo;
       titleInfo = mNodeInfoManager->GetNodeInfo(nsGkAtoms::title, nullptr,
-                                                kNameSpaceID_XHTML,
-                                                nsIDOMNode::ELEMENT_NODE);
+          kNameSpaceID_XHTML,
+          nsIDOMNode::ELEMENT_NODE);
       title = NS_NewHTMLTitleElement(titleInfo.forget());
-      if (!title)
+      if (!title) {
         return NS_OK;
-    }
+      }
 
-    head->AppendChildTo(title, true);
+      head->AppendChildTo(title, true);
+    }
+  } else {
+    return NS_OK;
   }
 
   return nsContentUtils::SetNodeTextContent(title, aTitle, false);

dom/base/nsDocument.h

@@ -1474,13 +1474,15 @@ protected:
   nsIContent* GetFirstBaseNodeWithHref();
   nsresult SetFirstBaseNodeWithHref(nsIContent *node);
 
-  // Get the first <title> element with the given IsNodeOfType type, or
-  // return null if there isn't one
-  nsIContent* GetTitleContent(uint32_t aNodeType);
-  // Find the first "title" element in the given IsNodeOfType type and
-  // append the concatenation of its text node children to aTitle. Do
-  // nothing if there is no such element.
-  void GetTitleFromElement(uint32_t aNodeType, nsAString& aTitle);
+  /**
+   * Returns the title element of the document as defined by the HTML
+   * specification, or null if there isn't one.  For documents whose root
+   * element is an <svg:svg>, this is the first <svg:title> element that's a
+   * child of the root.  For other documents, it's the first HTML title element
+   * in the document.
+   */
+  Element* GetTitleElement();
+
 public:
   // Get our title
   virtual void GetTitle(nsString& aTitle) override;

testing/web-platform/meta/html/dom/documents/dom-tree-accessors/document.title-09.html.ini

@@ -1,11 +0,0 @@
-[document.title-09.html]
-  type: testharness
-  [No title element in SVG document]
-    expected: FAIL
-
-  [Title element in SVG document]
-    expected: FAIL
-
-  [Title element not child of SVG root]
-    expected: FAIL
-

testing/web-platform/tests/html/dom/documents/dom-tree-accessors/document.title-09.html

@@ -5,21 +5,25 @@
 <div id="log"></div>
 <script>
 var SVG_NAMESPACE = "http://www.w3.org/2000/svg";
+var HTML_NAMESPACE = "http://www.w3.org/1999/xhtml";
 
 function newSVGDocument() {
   return document.implementation.createDocument(SVG_NAMESPACE, "svg");
 }
 
+function assertIsSVGTitle(element, expectedText) {
+  assert_equals(element.namespaceURI, SVG_NAMESPACE);
+  assert_equals(element.localName, "title");
+  assert_equals(element.textContent, expectedText);
+}
+
 test(function() {
   var doc = newSVGDocument();
   assert_equals(doc.title, "");
   var child = doc.createElementNS(SVG_NAMESPACE, "x-child");
   doc.documentElement.appendChild(child);
   doc.title = "foo";
-  var lastChild = doc.documentElement.lastChild;
-  assert_equals(lastChild.namespaceURI, SVG_NAMESPACE);
-  assert_equals(lastChild.localName, "title");
-  assert_equals(lastChild.textContent, "foo");
+  assertIsSVGTitle(doc.documentElement.firstChild, "foo");
   assert_equals(doc.title, "foo");
 }, "No title element in SVG document");
 
@@ -48,13 +52,46 @@ test(function() {
   child.appendChild(title);
   doc.documentElement.appendChild(child);
   assert_equals(doc.title, "");
+
+  // Now test that on setting, we create a new element and don't change the
+  // existing one
+  doc.title = "bar";
+  assert_equals(title.textContent, "foo");
+  assertIsSVGTitle(doc.documentElement.firstChild, "bar");
+  assert_equals(doc.title, "bar");
 }, "Title element not child of SVG root");
 
 test(function() {
   var doc = newSVGDocument();
-  var title = doc.createElement("title");
+  var title = doc.createElementNS(HTML_NAMESPACE, "title");
   title.textContent = "foo";
   doc.documentElement.appendChild(title);
   assert_equals(doc.title, "");
 }, "Title element not in SVG namespace");
+
+test(function() {
+  // "SVG" != "svg"
+  var doc = document.implementation.createDocument(SVG_NAMESPACE, "SVG", null);
+
+  // Per spec, this does nothing
+  doc.title = "foo";
+  assert_equals(doc.documentElement.childNodes.length, 0);
+  assert_equals(doc.title, "");
+
+  // An SVG title is ignored by .title
+  doc.documentElement.appendChild(doc.createElementNS(SVG_NAMESPACE, "title"));
+  doc.documentElement.lastChild.textContent = "foo";
+  assert_equals(doc.title, "");
+
+  // But an HTML title is respected
+  doc.documentElement.appendChild(doc.createElementNS(HTML_NAMESPACE, "title"));
+  doc.documentElement.lastChild.textContent = "bar";
+  assert_equals(doc.title, "bar");
+
+  // Even if it's not a child of the root
+  var div = doc.createElementNS(HTML_NAMESPACE, "div");
+  div.appendChild(doc.documentElement.lastChild);
+  doc.documentElement.appendChild(div);
+  assert_equals(doc.title, "bar");
+}, 'Root element not named "svg"');
 </script>