Bug 1011831 - Support <template> element in XHTML parser. r=hsivonen

content/base/src/FragmentOrElement.cpp

@@ -2597,9 +2597,10 @@ Serialize(FragmentOrElement* aRoot, bool aDescendentsOnly, nsAString& aOut)
 
       current = current->GetParentNode();
 
-      // Template case, if we are in a template's content, then the parent
-      // should be the host template element.
-      if (current->NodeType() == nsIDOMNode::DOCUMENT_FRAGMENT_NODE) {
+      // Handle template element. If the parent is a template's content,
+      // then adjust the parent to be the template element.
+      if (current != aRoot &&
+          current->NodeType() == nsIDOMNode::DOCUMENT_FRAGMENT_NODE) {
         DocumentFragment* frag = static_cast<DocumentFragment*>(current);
         nsIContent* fragHost = frag->GetHost();
         if (fragHost && nsNodeUtils::IsTemplateElement(fragHost)) {

content/base/src/nsDocumentEncoder.cpp

@@ -522,12 +522,12 @@ nsDocumentEncoder::SerializeToStringIterative(nsINode* aNode,
 {
   nsresult rv;
 
-  nsINode* node = aNode->GetFirstChild();
+  nsINode* node = nsNodeUtils::GetFirstChildOfTemplateOrNode(aNode);
   while (node) {
     nsINode* current = node;
     rv = SerializeNodeStart(current, 0, -1, aStr, current);
     NS_ENSURE_SUCCESS(rv, rv);
-    node = current->GetFirstChild();
+    node = nsNodeUtils::GetFirstChildOfTemplateOrNode(current);
     while (!node && current && current != aNode) {
       rv = SerializeNodeEnd(current, aStr);
       NS_ENSURE_SUCCESS(rv, rv);
@@ -536,6 +536,17 @@ nsDocumentEncoder::SerializeToStringIterative(nsINode* aNode,
       if (!node) {
         // Perhaps parent node has siblings.
         current = current->GetParentNode();
+
+        // Handle template element. If the parent is a template's content,
+        // then adjust the parent to be the template element.
+        if (current && current != aNode &&
+            current->NodeType() == nsIDOMNode::DOCUMENT_FRAGMENT_NODE) {
+          DocumentFragment* frag = static_cast<DocumentFragment*>(current);
+          nsIContent* host = frag->GetHost();
+          if (host && host->IsHTML(nsGkAtoms::_template)) {
+            current = host;
+          }
+        }
       }
     }
   }

content/xml/document/src/nsXMLContentSink.cpp

@@ -60,6 +60,7 @@
 #include "mozilla/dom/CDATASection.h"
 #include "mozilla/dom/Comment.h"
 #include "mozilla/dom/Element.h"
+#include "mozilla/dom/HTMLTemplateElement.h"
 #include "mozilla/dom/ProcessingInstruction.h"
 
 using namespace mozilla::dom;
@@ -848,7 +849,17 @@ nsXMLContentSink::PushContent(nsIContent *aContent)
   StackNode *sn = mContentStack.AppendElement();
   NS_ENSURE_TRUE(sn, NS_ERROR_OUT_OF_MEMORY);
 
-  sn->mContent = aContent;
+  nsIContent* contentToPush = aContent;
+
+  // When an XML parser would append a node to a template element, it
+  // must instead append it to the template element's template contents.
+  if (contentToPush->IsHTML(nsGkAtoms::_template)) {
+    HTMLTemplateElement* templateElement =
+      static_cast<HTMLTemplateElement*>(contentToPush);
+    contentToPush = templateElement->Content();
+  }
+
+  sn->mContent = contentToPush;
   sn->mNumFlushed = 0;
   return NS_OK;
 }
@@ -1076,8 +1087,13 @@ nsXMLContentSink::HandleEndElement(const char16_t *aName,
   nsContentUtils::SplitExpatName(aName, getter_AddRefs(debugNameSpacePrefix),
                                  getter_AddRefs(debugTagAtom),
                                  &debugNameSpaceID);
-  NS_ASSERTION(content->NodeInfo()->Equals(debugTagAtom, debugNameSpaceID),
-               "Wrong element being closed");
+  // Check if we are closing a template element because template
+  // elements do not get pushed on the stack, the template
+  // element content is pushed instead.
+  bool isTemplateElement = debugTagAtom == nsGkAtoms::_template &&
+                           debugNameSpaceID == kNameSpaceID_XHTML;
+  NS_ASSERTION(content->NodeInfo()->Equals(debugTagAtom, debugNameSpaceID) ||
+               isTemplateElement, "Wrong element being closed");
 #endif  
 
   result = CloseElement(content);

dom/tests/mochitest/webcomponents/mochitest.ini

@@ -17,6 +17,7 @@ support-files =
 [test_document_register_stack.html]
 [test_document_shared_registry.html]
 [test_template.html]
+[test_template_xhtml.html]
 [test_shadowroot.html]
 [test_shadowroot_inert_element.html]
 [test_shadowroot_style.html]

dom/tests/mochitest/webcomponents/test_template_xhtml.html

@@ -0,0 +1,46 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1011831
+-->
+<head>
+  <title>Test for template element</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1011831">Bug 1011831</a>
+<script>
+var docSrc =
+  '<!DOCTYPE html>' +
+  '<html xmlns="http://www.w3.org/1999/xhtml">' +
+    '<body>' +
+      '<template id="t">Content<span>Content</span></template>' +
+      '<div id="container"><template>One</template><div>Two</div></div>' +
+      '<template id="t2"></template>' +
+    '</body>' +
+  '</html>';
+
+var doc = (new DOMParser()).parseFromString(docSrc, 'application/xhtml+xml');
+
+var t = doc.getElementById("t");
+is(t.childNodes.length, 0, "Template should have no children.");
+is(t.content.childNodes.length, 2, "Template content should have two children, text node and a span.");
+
+// Test serialization of template element.
+is(t.innerHTML, 'Content<span xmlns="http://www.w3.org/1999/xhtml">Content</span>', "Template contents should be serialized.");
+is(t.outerHTML, '<template xmlns="http://www.w3.org/1999/xhtml" id="t">Content<span>Content</span></template>', "Template contents should be serialized.");
+
+var c = doc.getElementById("container");
+is(c.innerHTML, '<template xmlns="http://www.w3.org/1999/xhtml">One</template><div xmlns="http://www.w3.org/1999/xhtml">Two</div>', "Template contents should be serialized.");
+is(c.outerHTML, '<div xmlns="http://www.w3.org/1999/xhtml" id="container"><template>One</template><div>Two</div></div>', "Template contents should be serialized.");
+
+// Test setting innerHTML on template element.
+var t2 = doc.getElementById("t2");
+t2.innerHTML = 'Three<span>Four</span>';
+is(t2.childNodes.length, 0, "Setting innerHTML should append children into template content.");
+is(t2.content.childNodes.length, 2, "Setting innerHTML should append children into template content.");
+
+</script>
+</body>
+</html>