Adding upstream version 115.8.0esr.upstream/115.8.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 869 insertions, 0 deletions

diff --git a/dom/xul/nsXULContentSink.cpp b/dom/xul/nsXULContentSink.cpp
new file mode 100644
index 0000000000..a4c15c63cd
--- /dev/null
+++ b/dom/xul/nsXULContentSink.cpp
@@ -0,0 +1,869 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * An implementation for a Gecko-style content sink that knows how
+ * to build a content model (the "prototype" document) from XUL.
+ *
+ * For more information on XUL,
+ * see http://developer.mozilla.org/en/docs/XUL
+ */
+
+#include "nsXULContentSink.h"
+
+#include "jsfriendapi.h"
+
+#include "nsCOMPtr.h"
+#include "nsHTMLStyleSheet.h"
+#include "nsIContentSink.h"
+#include "mozilla/dom/Document.h"
+#include "nsIFormControl.h"
+#include "mozilla/dom/NodeInfo.h"
+#include "nsIScriptContext.h"
+#include "nsIScriptGlobalObject.h"
+#include "nsNameSpaceManager.h"
+#include "nsParserBase.h"
+#include "nsViewManager.h"
+#include "nsIScriptSecurityManager.h"
+#include "nsLayoutCID.h"
+#include "nsNetUtil.h"
+#include "nsString.h"
+#include "nsReadableUtils.h"
+#include "nsXULElement.h"
+#include "mozilla/Logging.h"
+#include "nsCRT.h"
+
+#include "nsXULPrototypeDocument.h"  // XXXbe temporary
+#include "mozilla/css/Loader.h"
+
+#include "nsUnicharUtils.h"
+#include "nsGkAtoms.h"
+#include "nsContentUtils.h"
+#include "nsAttrName.h"
+#include "nsXMLContentSink.h"
+#include "nsIScriptError.h"
+#include "nsContentTypeParser.h"
+
+static mozilla::LazyLogModule gContentSinkLog("nsXULContentSink");
+
+using namespace mozilla;
+using namespace mozilla::dom;
+//----------------------------------------------------------------------
+
+XULContentSinkImpl::ContextStack::ContextStack() : mTop(nullptr), mDepth(0) {}
+
+XULContentSinkImpl::ContextStack::~ContextStack() {
+  while (mTop) {
+    Entry* doomed = mTop;
+    mTop = mTop->mNext;
+    delete doomed;
+  }
+}
+
+void XULContentSinkImpl::ContextStack::Push(RefPtr<nsXULPrototypeNode>&& aNode,
+                                            State aState) {
+  mTop = new Entry(std::move(aNode), aState, mTop);
+  ++mDepth;
+}
+
+nsresult XULContentSinkImpl::ContextStack::Pop(State* aState) {
+  if (mDepth == 0) return NS_ERROR_UNEXPECTED;
+
+  Entry* entry = mTop;
+  mTop = mTop->mNext;
+  --mDepth;
+
+  *aState = entry->mState;
+  delete entry;
+
+  return NS_OK;
+}
+
+nsresult XULContentSinkImpl::ContextStack::GetTopNode(
+    RefPtr<nsXULPrototypeNode>& aNode) {
+  if (mDepth == 0) return NS_ERROR_UNEXPECTED;
+
+  aNode = mTop->mNode;
+  return NS_OK;
+}
+
+nsresult XULContentSinkImpl::ContextStack::GetTopChildren(
+    nsPrototypeArray** aChildren) {
+  if (mDepth == 0) return NS_ERROR_UNEXPECTED;
+
+  *aChildren = &(mTop->mChildren);
+  return NS_OK;
+}
+
+void XULContentSinkImpl::ContextStack::Clear() {
+  Entry* cur = mTop;
+  while (cur) {
+    // Release the root element (and its descendants).
+    Entry* next = cur->mNext;
+    delete cur;
+    cur = next;
+  }
+
+  mTop = nullptr;
+  mDepth = 0;
+}
+
+void XULContentSinkImpl::ContextStack::Traverse(
+    nsCycleCollectionTraversalCallback& aCb) {
+  nsCycleCollectionTraversalCallback& cb = aCb;
+  for (ContextStack::Entry* tmp = mTop; tmp; tmp = tmp->mNext) {
+    NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mNode)
+    NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mChildren)
+  }
+}
+
+//----------------------------------------------------------------------
+
+XULContentSinkImpl::XULContentSinkImpl()
+    : mText(nullptr),
+      mTextLength(0),
+      mTextSize(0),
+      mConstrainSize(true),
+      mState(eInProlog) {}
+
+XULContentSinkImpl::~XULContentSinkImpl() {
+  // The context stack _should_ be empty, unless something has gone wrong.
+  NS_ASSERTION(mContextStack.Depth() == 0, "Context stack not empty?");
+  mContextStack.Clear();
+
+  free(mText);
+}
+
+//----------------------------------------------------------------------
+// nsISupports interface
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(XULContentSinkImpl)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(XULContentSinkImpl)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mNodeInfoManager)
+  tmp->mContextStack.Clear();
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mPrototype)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mParser)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(XULContentSinkImpl)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mNodeInfoManager)
+  tmp->mContextStack.Traverse(cb);
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPrototype)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParser)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(XULContentSinkImpl)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIXMLContentSink)
+  NS_INTERFACE_MAP_ENTRY(nsIXMLContentSink)
+  NS_INTERFACE_MAP_ENTRY(nsIExpatSink)
+  NS_INTERFACE_MAP_ENTRY(nsIContentSink)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(XULContentSinkImpl)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(XULContentSinkImpl)
+
+//----------------------------------------------------------------------
+// nsIContentSink interface
+
+NS_IMETHODIMP
+XULContentSinkImpl::DidBuildModel(bool aTerminated) {
+  nsCOMPtr<Document> doc = do_QueryReferent(mDocument);
+  if (doc) {
+    mPrototype->NotifyLoadDone();
+    mDocument = nullptr;
+  }
+
+  // Drop our reference to the parser to get rid of a circular
+  // reference.
+  mParser = nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+XULContentSinkImpl::WillInterrupt(void) {
+  // XXX Notify the docshell, if necessary
+  return NS_OK;
+}
+
+void XULContentSinkImpl::WillResume() {
+  // XXX Notify the docshell, if necessary
+}
+
+NS_IMETHODIMP
+XULContentSinkImpl::SetParser(nsParserBase* aParser) {
+  mParser = aParser;
+  return NS_OK;
+}
+
+void XULContentSinkImpl::SetDocumentCharset(
+    NotNull<const Encoding*> aEncoding) {
+  nsCOMPtr<Document> doc = do_QueryReferent(mDocument);
+  if (doc) {
+    doc->SetDocumentCharacterSet(aEncoding);
+  }
+}
+
+nsISupports* XULContentSinkImpl::GetTarget() {
+  nsCOMPtr<Document> doc = do_QueryReferent(mDocument);
+  return ToSupports(doc);
+}
+
+//----------------------------------------------------------------------
+
+nsresult XULContentSinkImpl::Init(Document* aDocument,
+                                  nsXULPrototypeDocument* aPrototype) {
+  MOZ_ASSERT(aDocument != nullptr, "null ptr");
+  if (!aDocument) return NS_ERROR_NULL_POINTER;
+
+  mDocument = do_GetWeakReference(aDocument);
+  mPrototype = aPrototype;
+
+  mDocumentURL = mPrototype->GetURI();
+  mNodeInfoManager = aPrototype->GetNodeInfoManager();
+  if (!mNodeInfoManager) return NS_ERROR_UNEXPECTED;
+
+  mState = eInProlog;
+  return NS_OK;
+}
+
+//----------------------------------------------------------------------
+//
+// Text buffering
+//
+
+bool XULContentSinkImpl::IsDataInBuffer(char16_t* buffer, int32_t length) {
+  for (int32_t i = 0; i < length; ++i) {
+    if (buffer[i] == ' ' || buffer[i] == '\t' || buffer[i] == '\n' ||
+        buffer[i] == '\r')
+      continue;
+
+    return true;
+  }
+  return false;
+}
+
+nsresult XULContentSinkImpl::FlushText(bool aCreateTextNode) {
+  nsresult rv;
+
+  do {
+    // Don't do anything if there's no text to create a node from, or
+    // if they've told us not to create a text node
+    if (!mTextLength) break;
+
+    if (!aCreateTextNode) break;
+
+    RefPtr<nsXULPrototypeNode> node;
+    rv = mContextStack.GetTopNode(node);
+    if (NS_FAILED(rv)) return rv;
+
+    bool stripWhitespace = false;
+    if (node->mType == nsXULPrototypeNode::eType_Element) {
+      mozilla::dom::NodeInfo* nodeInfo =
+          static_cast<nsXULPrototypeElement*>(node.get())->mNodeInfo;
+
+      if (nodeInfo->NamespaceEquals(kNameSpaceID_XUL))
+        stripWhitespace = !nodeInfo->Equals(nsGkAtoms::label) &&
+                          !nodeInfo->Equals(nsGkAtoms::description);
+    }
+
+    // Don't bother if there's nothing but whitespace.
+    if (stripWhitespace && !IsDataInBuffer(mText, mTextLength)) break;
+
+    // Don't bother if we're not in XUL document body
+    if (mState != eInDocumentElement || mContextStack.Depth() == 0) break;
+
+    RefPtr<nsXULPrototypeText> text = new nsXULPrototypeText();
+    text->mValue.Assign(mText, mTextLength);
+    if (stripWhitespace) text->mValue.Trim(" \t\n\r");
+
+    // hook it up
+    nsPrototypeArray* children = nullptr;
+    rv = mContextStack.GetTopChildren(&children);
+    if (NS_FAILED(rv)) return rv;
+
+    children->AppendElement(text.forget());
+  } while (0);
+
+  // Reset our text buffer
+  mTextLength = 0;
+  return NS_OK;
+}
+
+//----------------------------------------------------------------------
+
+nsresult XULContentSinkImpl::NormalizeAttributeString(
+    const char16_t* aExpatName, nsAttrName& aName) {
+  int32_t nameSpaceID;
+  RefPtr<nsAtom> prefix, localName;
+  nsContentUtils::SplitExpatName(aExpatName, getter_AddRefs(prefix),
+                                 getter_AddRefs(localName), &nameSpaceID);
+
+  if (nameSpaceID == kNameSpaceID_None) {
+    aName.SetTo(localName);
+
+    return NS_OK;
+  }
+
+  RefPtr<mozilla::dom::NodeInfo> ni;
+  ni = mNodeInfoManager->GetNodeInfo(localName, prefix, nameSpaceID,
+                                     nsINode::ATTRIBUTE_NODE);
+  aName.SetTo(ni);
+
+  return NS_OK;
+}
+
+/**** BEGIN NEW APIs ****/
+
+NS_IMETHODIMP
+XULContentSinkImpl::HandleStartElement(const char16_t* aName,
+                                       const char16_t** aAtts,
+                                       uint32_t aAttsCount,
+                                       uint32_t aLineNumber,
+                                       uint32_t aColumnNumber) {
+  // XXX Hopefully the parser will flag this before we get here. If
+  // we're in the epilog, there should be no new elements
+  MOZ_ASSERT(mState != eInEpilog, "tag in XUL doc epilog");
+  MOZ_ASSERT(aAttsCount % 2 == 0, "incorrect aAttsCount");
+
+  // Adjust aAttsCount so it's the actual number of attributes
+  aAttsCount /= 2;
+
+  if (mState == eInEpilog) return NS_ERROR_UNEXPECTED;
+
+  if (mState != eInScript) {
+    FlushText();
+  }
+
+  int32_t nameSpaceID;
+  RefPtr<nsAtom> prefix, localName;
+  nsContentUtils::SplitExpatName(aName, getter_AddRefs(prefix),
+                                 getter_AddRefs(localName), &nameSpaceID);
+
+  RefPtr<mozilla::dom::NodeInfo> nodeInfo;
+  nodeInfo = mNodeInfoManager->GetNodeInfo(localName, prefix, nameSpaceID,
+                                           nsINode::ELEMENT_NODE);
+
+  nsresult rv = NS_OK;
+  switch (mState) {
+    case eInProlog:
+      // We're the root document element
+      rv = OpenRoot(aAtts, aAttsCount, nodeInfo);
+      break;
+
+    case eInDocumentElement:
+      rv = OpenTag(aAtts, aAttsCount, aLineNumber, nodeInfo);
+      break;
+
+    case eInEpilog:
+    case eInScript:
+      MOZ_LOG(
+          gContentSinkLog, LogLevel::Warning,
+          ("xul: warning: unexpected tags in epilog at line %d", aLineNumber));
+      rv = NS_ERROR_UNEXPECTED;  // XXX
+      break;
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+XULContentSinkImpl::HandleEndElement(const char16_t* aName) {
+  // Never EVER return anything but NS_OK or
+  // NS_ERROR_HTMLPARSER_BLOCK from this method. Doing so will blow
+  // the parser's little mind all over the planet.
+  nsresult rv;
+
+  RefPtr<nsXULPrototypeNode> node;
+  rv = mContextStack.GetTopNode(node);
+
+  if (NS_FAILED(rv)) {
+    return NS_OK;
+  }
+
+  switch (node->mType) {
+    case nsXULPrototypeNode::eType_Element: {
+      // Flush any text _now_, so that we'll get text nodes created
+      // before popping the stack.
+      FlushText();
+
+      // Pop the context stack and do prototype hookup.
+      nsPrototypeArray* children = nullptr;
+      rv = mContextStack.GetTopChildren(&children);
+      if (NS_FAILED(rv)) return rv;
+
+      nsXULPrototypeElement* element =
+          static_cast<nsXULPrototypeElement*>(node.get());
+
+      int32_t count = children->Length();
+      if (count) {
+        element->mChildren.SetCapacity(count);
+
+        for (int32_t i = 0; i < count; ++i)
+          element->mChildren.AppendElement(children->ElementAt(i));
+      }
+    } break;
+
+    case nsXULPrototypeNode::eType_Script: {
+      nsXULPrototypeScript* script =
+          static_cast<nsXULPrototypeScript*>(node.get());
+
+      // If given a src= attribute, we must ignore script tag content.
+      if (!script->mSrcURI && !script->HasStencil()) {
+        nsCOMPtr<Document> doc = do_QueryReferent(mDocument);
+
+        script->mOutOfLine = false;
+        if (doc) {
+          script->Compile(mText, mTextLength, JS::SourceOwnership::Borrowed,
+                          mDocumentURL, script->mLineNo, doc);
+        }
+      }
+
+      FlushText(false);
+    } break;
+
+    default:
+      NS_ERROR("didn't expect that");
+      break;
+  }
+
+  rv = mContextStack.Pop(&mState);
+  NS_ASSERTION(NS_SUCCEEDED(rv), "context stack corrupted");
+  if (NS_FAILED(rv)) return rv;
+
+  if (mContextStack.Depth() == 0) {
+    // The root element should -always- be an element, because
+    // it'll have been created via XULContentSinkImpl::OpenRoot().
+    NS_ASSERTION(node->mType == nsXULPrototypeNode::eType_Element,
+                 "root is not an element");
+    if (node->mType != nsXULPrototypeNode::eType_Element)
+      return NS_ERROR_UNEXPECTED;
+
+    // Now that we're done parsing, set the prototype document's
+    // root element. This transfers ownership of the prototype
+    // element tree to the prototype document.
+    nsXULPrototypeElement* element =
+        static_cast<nsXULPrototypeElement*>(node.get());
+
+    mPrototype->SetRootElement(element);
+    mState = eInEpilog;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+XULContentSinkImpl::HandleComment(const char16_t* aName) {
+  FlushText();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+XULContentSinkImpl::HandleCDataSection(const char16_t* aData,
+                                       uint32_t aLength) {
+  FlushText();
+  return AddText(aData, aLength);
+}
+
+NS_IMETHODIMP
+XULContentSinkImpl::HandleDoctypeDecl(const nsAString& aSubset,
+                                      const nsAString& aName,
+                                      const nsAString& aSystemId,
+                                      const nsAString& aPublicId,
+                                      nsISupports* aCatalogData) {
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+XULContentSinkImpl::HandleCharacterData(const char16_t* aData,
+                                        uint32_t aLength) {
+  if (aData && mState != eInProlog && mState != eInEpilog) {
+    return AddText(aData, aLength);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+XULContentSinkImpl::HandleProcessingInstruction(const char16_t* aTarget,
+                                                const char16_t* aData) {
+  FlushText();
+
+  const nsDependentString target(aTarget);
+  const nsDependentString data(aData);
+
+  // Note: the created nsXULPrototypePI has mRefCnt == 1
+  RefPtr<nsXULPrototypePI> pi = new nsXULPrototypePI();
+  pi->mTarget = target;
+  pi->mData = data;
+
+  if (mState == eInProlog) {
+    // Note: passing in already addrefed pi
+    return mPrototype->AddProcessingInstruction(pi);
+  }
+
+  nsresult rv;
+  nsPrototypeArray* children = nullptr;
+  rv = mContextStack.GetTopChildren(&children);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // XXX(Bug 1631371) Check if this should use a fallible operation as it
+  // pretended earlier.
+  children->AppendElement(pi);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+XULContentSinkImpl::HandleXMLDeclaration(const char16_t* aVersion,
+                                         const char16_t* aEncoding,
+                                         int32_t aStandalone) {
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+XULContentSinkImpl::ReportError(const char16_t* aErrorText,
+                                const char16_t* aSourceText,
+                                nsIScriptError* aError, bool* _retval) {
+  MOZ_ASSERT(aError && aSourceText && aErrorText, "Check arguments!!!");
+
+  // The expat driver should report the error.
+  *_retval = true;
+
+  nsresult rv = NS_OK;
+
+  // make sure to empty the context stack so that
+  // <parsererror> could become the root element.
+  mContextStack.Clear();
+
+  mState = eInProlog;
+
+  // Clear any buffered-up text we have.  It's enough to set the length to 0.
+  // The buffer itself is allocated when we're created and deleted in our
+  // destructor, so don't mess with it.
+  mTextLength = 0;
+
+  // return leaving the document empty if we're asked to not add a <parsererror>
+  // root node
+  nsCOMPtr<Document> idoc = do_QueryReferent(mDocument);
+  if (idoc && idoc->SuppressParserErrorElement()) {
+    return NS_OK;
+  };
+
+  const char16_t* noAtts[] = {0, 0};
+
+  constexpr auto errorNs =
+      u"http://www.mozilla.org/newlayout/xml/parsererror.xml"_ns;
+
+  nsAutoString parsererror(errorNs);
+  parsererror.Append((char16_t)0xFFFF);
+  parsererror.AppendLiteral("parsererror");
+
+  rv = HandleStartElement(parsererror.get(), noAtts, 0, 0, 0);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = HandleCharacterData(aErrorText, NS_strlen(aErrorText));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoString sourcetext(errorNs);
+  sourcetext.Append((char16_t)0xFFFF);
+  sourcetext.AppendLiteral("sourcetext");
+
+  rv = HandleStartElement(sourcetext.get(), noAtts, 0, 0, 0);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = HandleCharacterData(aSourceText, NS_strlen(aSourceText));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = HandleEndElement(sourcetext.get());
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = HandleEndElement(parsererror.get());
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return rv;
+}
+
+nsresult XULContentSinkImpl::OpenRoot(const char16_t** aAttributes,
+                                      const uint32_t aAttrLen,
+                                      mozilla::dom::NodeInfo* aNodeInfo) {
+  NS_ASSERTION(mState == eInProlog, "how'd we get here?");
+  if (mState != eInProlog) return NS_ERROR_UNEXPECTED;
+
+  if (aNodeInfo->Equals(nsGkAtoms::script, kNameSpaceID_XHTML) ||
+      aNodeInfo->Equals(nsGkAtoms::script, kNameSpaceID_XUL)) {
+    MOZ_LOG(gContentSinkLog, LogLevel::Error,
+            ("xul: script tag not allowed as root content element"));
+
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  // Create the element
+  RefPtr<nsXULPrototypeElement> element = new nsXULPrototypeElement(aNodeInfo);
+
+  // Add the attributes
+  nsresult rv = AddAttributes(aAttributes, aAttrLen, element);
+  if (NS_FAILED(rv)) return rv;
+
+  // Push the element onto the context stack, so that child
+  // containers will hook up to us as their parent.
+  mContextStack.Push(std::move(element), mState);
+
+  mState = eInDocumentElement;
+  return NS_OK;
+}
+
+nsresult XULContentSinkImpl::OpenTag(const char16_t** aAttributes,
+                                     const uint32_t aAttrLen,
+                                     const uint32_t aLineNumber,
+                                     mozilla::dom::NodeInfo* aNodeInfo) {
+  // Create the element
+  RefPtr<nsXULPrototypeElement> element = new nsXULPrototypeElement(aNodeInfo);
+
+  // Link this element to its parent.
+  nsPrototypeArray* children = nullptr;
+  nsresult rv = mContextStack.GetTopChildren(&children);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // Add the attributes
+  rv = AddAttributes(aAttributes, aAttrLen, element);
+  if (NS_FAILED(rv)) return rv;
+
+  children->AppendElement(element);
+
+  if (aNodeInfo->Equals(nsGkAtoms::script, kNameSpaceID_XHTML) ||
+      aNodeInfo->Equals(nsGkAtoms::script, kNameSpaceID_XUL)) {
+    // Do scripty things now
+    rv = OpenScript(aAttributes, aLineNumber);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    NS_ASSERTION(mState == eInScript || mState == eInDocumentElement,
+                 "Unexpected state");
+    if (mState == eInScript) {
+      // OpenScript has pushed the nsPrototypeScriptElement onto the
+      // stack, so we're done.
+      return NS_OK;
+    }
+  }
+
+  // Push the element onto the context stack, so that child
+  // containers will hook up to us as their parent.
+  mContextStack.Push(std::move(element), mState);
+
+  mState = eInDocumentElement;
+  return NS_OK;
+}
+
+nsresult XULContentSinkImpl::OpenScript(const char16_t** aAttributes,
+                                        const uint32_t aLineNumber) {
+  bool isJavaScript = true;
+  nsresult rv;
+
+  // Look for SRC attribute and look for a LANGUAGE attribute
+  nsAutoString src;
+  while (*aAttributes) {
+    const nsDependentString key(aAttributes[0]);
+    if (key.EqualsLiteral("src")) {
+      src.Assign(aAttributes[1]);
+    } else if (key.EqualsLiteral("type")) {
+      nsDependentString str(aAttributes[1]);
+      nsContentTypeParser parser(str);
+      nsAutoString mimeType;
+      rv = parser.GetType(mimeType);
+      if (NS_FAILED(rv)) {
+        if (rv == NS_ERROR_INVALID_ARG) {
+          // Fail immediately rather than checking if later things
+          // are okay.
+          return NS_OK;
+        }
+        // We do want the warning here
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+
+      // NOTE(emilio): Module scripts don't pass this test, aren't cached yet.
+      // If they become cached, then we need to tweak
+      // PrototypeDocumentContentSink and remove the special cases there.
+      if (nsContentUtils::IsJavascriptMIMEType(mimeType)) {
+        isJavaScript = true;
+
+        // Get the version string, and ensure that JavaScript supports it.
+        nsAutoString versionName;
+        rv = parser.GetParameter("version", versionName);
+
+        if (NS_SUCCEEDED(rv)) {
+          nsContentUtils::ReportToConsoleNonLocalized(
+              u"Versioned JavaScripts are no longer supported. "
+              "Please remove the version parameter."_ns,
+              nsIScriptError::errorFlag, "XUL Document"_ns, nullptr,
+              mDocumentURL, u""_ns, aLineNumber);
+          isJavaScript = false;
+        } else if (rv != NS_ERROR_INVALID_ARG) {
+          return rv;
+        }
+      } else {
+        isJavaScript = false;
+      }
+    } else if (key.EqualsLiteral("language")) {
+      // Language is deprecated, and the impl in ScriptLoader ignores the
+      // various version strings anyway.  So we make no attempt to support
+      // languages other than JS for language=
+      nsAutoString lang(aAttributes[1]);
+      if (nsContentUtils::IsJavaScriptLanguage(lang)) {
+        isJavaScript = true;
+      }
+    }
+    aAttributes += 2;
+  }
+
+  // Don't process scripts that aren't JavaScript.
+  if (!isJavaScript) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<Document> doc(do_QueryReferent(mDocument));
+  nsCOMPtr<nsIScriptGlobalObject> globalObject;
+  if (doc) globalObject = do_QueryInterface(doc->GetWindow());
+  RefPtr<nsXULPrototypeScript> script = new nsXULPrototypeScript(aLineNumber);
+
+  // If there is a SRC attribute...
+  if (!src.IsEmpty()) {
+    // Use the SRC attribute value to load the URL
+    rv = NS_NewURI(getter_AddRefs(script->mSrcURI), src, nullptr, mDocumentURL);
+
+    // Check if this document is allowed to load a script from this source
+    // NOTE: if we ever allow scripts added via the DOM to run, we need to
+    // add a CheckLoadURI call for that as well.
+    if (NS_SUCCEEDED(rv)) {
+      if (!mSecMan)
+        mSecMan = do_GetService(NS_SCRIPTSECURITYMANAGER_CONTRACTID, &rv);
+      if (NS_SUCCEEDED(rv)) {
+        nsCOMPtr<Document> doc = do_QueryReferent(mDocument, &rv);
+
+        if (NS_SUCCEEDED(rv)) {
+          rv = mSecMan->CheckLoadURIWithPrincipal(
+              doc->NodePrincipal(), script->mSrcURI,
+              nsIScriptSecurityManager::ALLOW_CHROME, doc->InnerWindowID());
+        }
+      }
+    }
+
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    // Attempt to deserialize an out-of-line script from the FastLoad
+    // file right away.  Otherwise we'll end up reloading the script and
+    // corrupting the FastLoad file trying to serialize it, in the case
+    // where it's already there.
+    script->DeserializeOutOfLine(nullptr, mPrototype);
+  }
+
+  nsPrototypeArray* children = nullptr;
+  rv = mContextStack.GetTopChildren(&children);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  children->AppendElement(script);
+
+  mConstrainSize = false;
+
+  mContextStack.Push(script, mState);
+  mState = eInScript;
+
+  return NS_OK;
+}
+
+nsresult XULContentSinkImpl::AddAttributes(const char16_t** aAttributes,
+                                           const uint32_t aAttrLen,
+                                           nsXULPrototypeElement* aElement) {
+  // Add tag attributes to the element
+  nsresult rv;
+
+  // Create storage for the attributes
+  nsXULPrototypeAttribute* attrs = nullptr;
+  if (aAttrLen > 0) {
+    attrs = aElement->mAttributes.AppendElements(aAttrLen);
+  }
+
+  // Copy the attributes into the prototype
+  uint32_t i;
+  for (i = 0; i < aAttrLen; ++i) {
+    rv = NormalizeAttributeString(aAttributes[i * 2], attrs[i].mName);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = aElement->SetAttrAt(i, nsDependentString(aAttributes[i * 2 + 1]),
+                             mDocumentURL);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (MOZ_LOG_TEST(gContentSinkLog, LogLevel::Debug)) {
+      nsAutoString extraWhiteSpace;
+      int32_t cnt = mContextStack.Depth();
+      while (--cnt >= 0) extraWhiteSpace.AppendLiteral("  ");
+      nsAutoString qnameC, valueC;
+      qnameC.Assign(aAttributes[0]);
+      valueC.Assign(aAttributes[1]);
+      MOZ_LOG(gContentSinkLog, LogLevel::Debug,
+              ("xul: %.5d. %s    %s=%s",
+               -1,  // XXX pass in line number
+               NS_ConvertUTF16toUTF8(extraWhiteSpace).get(),
+               NS_ConvertUTF16toUTF8(qnameC).get(),
+               NS_ConvertUTF16toUTF8(valueC).get()));
+    }
+  }
+
+  return NS_OK;
+}
+
+nsresult XULContentSinkImpl::AddText(const char16_t* aText, int32_t aLength) {
+  // Create buffer when we first need it
+  if (0 == mTextSize) {
+    mText = (char16_t*)malloc(sizeof(char16_t) * 4096);
+    if (nullptr == mText) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+    mTextSize = 4096;
+  }
+
+  // Copy data from string into our buffer; flush buffer when it fills up
+  int32_t offset = 0;
+  while (0 != aLength) {
+    int32_t amount = mTextSize - mTextLength;
+    if (amount > aLength) {
+      amount = aLength;
+    }
+    if (0 == amount) {
+      if (mConstrainSize) {
+        nsresult rv = FlushText();
+        if (NS_OK != rv) {
+          return rv;
+        }
+      } else {
+        CheckedInt32 size = mTextSize;
+        size += aLength;
+        if (!size.isValid()) {
+          return NS_ERROR_OUT_OF_MEMORY;
+        }
+        mTextSize = size.value();
+
+        mText = (char16_t*)realloc(mText, sizeof(char16_t) * mTextSize);
+        if (nullptr == mText) {
+          return NS_ERROR_OUT_OF_MEMORY;
+        }
+      }
+    }
+    memcpy(&mText[mTextLength], aText + offset, sizeof(char16_t) * amount);
+
+    mTextLength += amount;
+    offset += amount;
+    aLength -= amount;
+  }
+
+  return NS_OK;
+}