Adding upstream version 86.0.1.upstream/86.0.1upstream

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

1 files changed, 731 insertions, 0 deletions

diff --git a/dom/serializers/nsXHTMLContentSerializer.cpp b/dom/serializers/nsXHTMLContentSerializer.cpp
new file mode 100644
index 0000000000..415db224ef
--- /dev/null
+++ b/dom/serializers/nsXHTMLContentSerializer.cpp
@@ -0,0 +1,731 @@
+/* -*- 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/. */
+
+/*
+ * nsIContentSerializer implementation that can be used with an
+ * nsIDocumentEncoder to convert an XHTML (not HTML!) DOM to an XHTML
+ * string that could be parsed into more or less the original DOM.
+ */
+
+#include "nsXHTMLContentSerializer.h"
+
+#include "mozilla/dom/Element.h"
+#include "nsIContent.h"
+#include "mozilla/dom/Document.h"
+#include "nsElementTable.h"
+#include "nsNameSpaceManager.h"
+#include "nsString.h"
+#include "nsUnicharUtils.h"
+#include "nsIDocumentEncoder.h"
+#include "nsGkAtoms.h"
+#include "nsIURI.h"
+#include "nsNetUtil.h"
+#include "nsEscape.h"
+#include "nsCRT.h"
+#include "nsContentUtils.h"
+#include "nsIScriptElement.h"
+#include "nsStubMutationObserver.h"
+#include "nsAttrName.h"
+#include "nsComputedDOMStyle.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+static const int32_t kLongLineLen = 128;
+
+#define kXMLNS "xmlns"
+
+nsresult NS_NewXHTMLContentSerializer(nsIContentSerializer** aSerializer) {
+  RefPtr<nsXHTMLContentSerializer> it = new nsXHTMLContentSerializer();
+  it.forget(aSerializer);
+  return NS_OK;
+}
+
+nsXHTMLContentSerializer::nsXHTMLContentSerializer()
+    : mIsHTMLSerializer(false),
+      mIsCopying(false),
+      mDisableEntityEncoding(0),
+      mRewriteEncodingDeclaration(false),
+      mIsFirstChildOfOL(false) {}
+
+nsXHTMLContentSerializer::~nsXHTMLContentSerializer() {
+  NS_ASSERTION(mOLStateStack.IsEmpty(), "Expected OL State stack to be empty");
+}
+
+NS_IMETHODIMP
+nsXHTMLContentSerializer::Init(uint32_t aFlags, uint32_t aWrapColumn,
+                               const Encoding* aEncoding, bool aIsCopying,
+                               bool aRewriteEncodingDeclaration,
+                               bool* aNeedsPreformatScanning,
+                               nsAString& aOutput) {
+  // The previous version of the HTML serializer did implicit wrapping
+  // when there is no flags, so we keep wrapping in order to keep
+  // compatibility with the existing calling code
+  // XXXLJ perhaps should we remove this default settings later ?
+  if (aFlags & nsIDocumentEncoder::OutputFormatted) {
+    aFlags = aFlags | nsIDocumentEncoder::OutputWrap;
+  }
+
+  nsresult rv;
+  rv = nsXMLContentSerializer::Init(aFlags, aWrapColumn, aEncoding, aIsCopying,
+                                    aRewriteEncodingDeclaration,
+                                    aNeedsPreformatScanning, aOutput);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  mRewriteEncodingDeclaration = aRewriteEncodingDeclaration;
+  mIsCopying = aIsCopying;
+  mIsFirstChildOfOL = false;
+  mInBody = 0;
+  mDisableEntityEncoding = 0;
+  mBodyOnly = (mFlags & nsIDocumentEncoder::OutputBodyOnly);
+
+  return NS_OK;
+}
+
+// See if the string has any lines longer than longLineLen:
+// if so, we presume formatting is wonky (e.g. the node has been edited)
+// and we'd better rewrap the whole text node.
+bool nsXHTMLContentSerializer::HasLongLines(const nsString& text,
+                                            int32_t& aLastNewlineOffset) {
+  uint32_t start = 0;
+  uint32_t theLen = text.Length();
+  bool rv = false;
+  aLastNewlineOffset = kNotFound;
+  for (start = 0; start < theLen;) {
+    int32_t eol = text.FindChar('\n', start);
+    if (eol < 0) {
+      eol = text.Length();
+    } else {
+      aLastNewlineOffset = eol;
+    }
+    if (int32_t(eol - start) > kLongLineLen) rv = true;
+    start = eol + 1;
+  }
+  return rv;
+}
+
+NS_IMETHODIMP
+nsXHTMLContentSerializer::AppendText(nsIContent* aText, int32_t aStartOffset,
+                                     int32_t aEndOffset) {
+  NS_ENSURE_ARG(aText);
+  NS_ENSURE_STATE(mOutput);
+
+  nsAutoString data;
+  nsresult rv;
+
+  rv = AppendTextData(aText, aStartOffset, aEndOffset, data, true);
+  if (NS_FAILED(rv)) return NS_ERROR_FAILURE;
+
+  if (mDoRaw || PreLevel() > 0) {
+    NS_ENSURE_TRUE(AppendToStringConvertLF(data, *mOutput),
+                   NS_ERROR_OUT_OF_MEMORY);
+  } else if (mDoFormat) {
+    NS_ENSURE_TRUE(AppendToStringFormatedWrapped(data, *mOutput),
+                   NS_ERROR_OUT_OF_MEMORY);
+  } else if (mDoWrap) {
+    NS_ENSURE_TRUE(AppendToStringWrapped(data, *mOutput),
+                   NS_ERROR_OUT_OF_MEMORY);
+  } else {
+    int32_t lastNewlineOffset = kNotFound;
+    if (HasLongLines(data, lastNewlineOffset)) {
+      // We have long lines, rewrap
+      mDoWrap = true;
+      bool result = AppendToStringWrapped(data, *mOutput);
+      mDoWrap = false;
+      NS_ENSURE_TRUE(result, NS_ERROR_OUT_OF_MEMORY);
+    } else {
+      NS_ENSURE_TRUE(AppendToStringConvertLF(data, *mOutput),
+                     NS_ERROR_OUT_OF_MEMORY);
+    }
+  }
+
+  return NS_OK;
+}
+
+bool nsXHTMLContentSerializer::SerializeAttributes(
+    Element* aElement, Element* aOriginalElement, nsAString& aTagPrefix,
+    const nsAString& aTagNamespaceURI, nsAtom* aTagName, nsAString& aStr,
+    uint32_t aSkipAttr, bool aAddNSAttr) {
+  nsresult rv;
+  uint32_t index, count;
+  nsAutoString prefixStr, uriStr, valueStr;
+  nsAutoString xmlnsStr;
+  xmlnsStr.AssignLiteral(kXMLNS);
+
+  int32_t contentNamespaceID = aElement->GetNameSpaceID();
+
+  MaybeSerializeIsValue(aElement, aStr);
+
+  // this method is not called by nsHTMLContentSerializer
+  // so we don't have to check HTML element, just XHTML
+
+  if (mIsCopying && kNameSpaceID_XHTML == contentNamespaceID) {
+    // Need to keep track of OL and LI elements in order to get ordinal number
+    // for the LI.
+    if (aTagName == nsGkAtoms::ol) {
+      // We are copying and current node is an OL;
+      // Store its start attribute value in olState->startVal.
+      nsAutoString start;
+      int32_t startAttrVal = 0;
+      aElement->GetAttr(kNameSpaceID_None, nsGkAtoms::start, start);
+      if (!start.IsEmpty()) {
+        nsresult rv = NS_OK;
+        startAttrVal = start.ToInteger(&rv);
+        // If OL has "start" attribute, first LI element has to start with that
+        // value Therefore subtracting 1 as all the LI elements are incrementing
+        // it before using it; In failure of ToInteger(), default StartAttrValue
+        // to 0.
+        if (NS_SUCCEEDED(rv))
+          --startAttrVal;
+        else
+          startAttrVal = 0;
+      }
+      olState state(startAttrVal, true);
+      mOLStateStack.AppendElement(state);
+    } else if (aTagName == nsGkAtoms::li) {
+      mIsFirstChildOfOL = IsFirstChildOfOL(aOriginalElement);
+      if (mIsFirstChildOfOL) {
+        // If OL is parent of this LI, serialize attributes in different manner.
+        NS_ENSURE_TRUE(SerializeLIValueAttribute(aElement, aStr), false);
+      }
+    }
+  }
+
+  // If we had to add a new namespace declaration, serialize
+  // and push it on the namespace stack
+  if (aAddNSAttr) {
+    if (aTagPrefix.IsEmpty()) {
+      // Serialize default namespace decl
+      NS_ENSURE_TRUE(
+          SerializeAttr(u""_ns, xmlnsStr, aTagNamespaceURI, aStr, true), false);
+    } else {
+      // Serialize namespace decl
+      NS_ENSURE_TRUE(
+          SerializeAttr(xmlnsStr, aTagPrefix, aTagNamespaceURI, aStr, true),
+          false);
+    }
+    PushNameSpaceDecl(aTagPrefix, aTagNamespaceURI, aOriginalElement);
+  }
+
+  count = aElement->GetAttrCount();
+
+  // Now serialize each of the attributes
+  // XXX Unfortunately we need a namespace manager to get
+  // attribute URIs.
+  for (index = 0; index < count; index++) {
+    if (aSkipAttr == index) {
+      continue;
+    }
+
+    dom::BorrowedAttrInfo info = aElement->GetAttrInfoAt(index);
+    const nsAttrName* name = info.mName;
+
+    int32_t namespaceID = name->NamespaceID();
+    nsAtom* attrName = name->LocalName();
+    nsAtom* attrPrefix = name->GetPrefix();
+
+    // Filter out any attribute starting with [-|_]moz
+    nsDependentAtomString attrNameStr(attrName);
+    if (StringBeginsWith(attrNameStr, u"_moz"_ns) ||
+        StringBeginsWith(attrNameStr, u"-moz"_ns)) {
+      continue;
+    }
+
+    if (attrPrefix) {
+      attrPrefix->ToString(prefixStr);
+    } else {
+      prefixStr.Truncate();
+    }
+
+    bool addNSAttr = false;
+    if (kNameSpaceID_XMLNS != namespaceID) {
+      nsContentUtils::NameSpaceManager()->GetNameSpaceURI(namespaceID, uriStr);
+      addNSAttr = ConfirmPrefix(prefixStr, uriStr, aOriginalElement, true);
+    }
+
+    info.mValue->ToString(valueStr);
+
+    nsDependentAtomString nameStr(attrName);
+    bool isJS = false;
+
+    if (kNameSpaceID_XHTML == contentNamespaceID) {
+      if (mIsCopying && mIsFirstChildOfOL && (aTagName == nsGkAtoms::li) &&
+          (attrName == nsGkAtoms::value)) {
+        // This is handled separately in SerializeLIValueAttribute()
+        continue;
+      }
+
+      isJS = IsJavaScript(aElement, attrName, namespaceID, valueStr);
+
+      if (namespaceID == kNameSpaceID_None &&
+          ((attrName == nsGkAtoms::href) || (attrName == nsGkAtoms::src))) {
+        // Make all links absolute when converting only the selection:
+        if (mFlags & nsIDocumentEncoder::OutputAbsoluteLinks) {
+          // Would be nice to handle OBJECT tags,
+          // but that gets more complicated since we have to
+          // search the tag list for CODEBASE as well.
+          // For now, just leave them relative.
+          nsIURI* uri = aElement->GetBaseURI();
+          if (uri) {
+            nsAutoString absURI;
+            rv = NS_MakeAbsoluteURI(absURI, valueStr, uri);
+            if (NS_SUCCEEDED(rv)) {
+              valueStr = absURI;
+            }
+          }
+        }
+      }
+
+      if (mRewriteEncodingDeclaration && aTagName == nsGkAtoms::meta &&
+          attrName == nsGkAtoms::content) {
+        // If we're serializing a <meta http-equiv="content-type">,
+        // use the proper value, rather than what's in the document.
+        nsAutoString header;
+        aElement->GetAttr(kNameSpaceID_None, nsGkAtoms::httpEquiv, header);
+        if (header.LowerCaseEqualsLiteral("content-type")) {
+          valueStr =
+              u"text/html; charset="_ns + NS_ConvertASCIItoUTF16(mCharset);
+        }
+      }
+
+      // Expand shorthand attribute.
+      if (namespaceID == kNameSpaceID_None &&
+          IsShorthandAttr(attrName, aTagName) && valueStr.IsEmpty()) {
+        valueStr = nameStr;
+      }
+    } else {
+      isJS = IsJavaScript(aElement, attrName, namespaceID, valueStr);
+    }
+
+    NS_ENSURE_TRUE(SerializeAttr(prefixStr, nameStr, valueStr, aStr, !isJS),
+                   false);
+
+    if (addNSAttr) {
+      NS_ASSERTION(!prefixStr.IsEmpty(),
+                   "Namespaced attributes must have a prefix");
+      NS_ENSURE_TRUE(SerializeAttr(xmlnsStr, prefixStr, uriStr, aStr, true),
+                     false);
+      PushNameSpaceDecl(prefixStr, uriStr, aOriginalElement);
+    }
+  }
+
+  return true;
+}
+
+bool nsXHTMLContentSerializer::AfterElementStart(nsIContent* aContent,
+                                                 nsIContent* aOriginalElement,
+                                                 nsAString& aStr) {
+  if (mRewriteEncodingDeclaration && aContent->IsHTMLElement(nsGkAtoms::head)) {
+    // Check if there already are any content-type meta children.
+    // If there are, they will be modified to use the correct charset.
+    // If there aren't, we'll insert one here.
+    bool hasMeta = false;
+    for (nsIContent* child = aContent->GetFirstChild(); child;
+         child = child->GetNextSibling()) {
+      if (child->IsHTMLElement(nsGkAtoms::meta) &&
+          child->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::content)) {
+        nsAutoString header;
+        child->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::httpEquiv,
+                                    header);
+
+        if (header.LowerCaseEqualsLiteral("content-type")) {
+          hasMeta = true;
+          break;
+        }
+      }
+    }
+
+    if (!hasMeta) {
+      NS_ENSURE_TRUE(AppendNewLineToString(aStr), false);
+      if (mDoFormat) {
+        NS_ENSURE_TRUE(AppendIndentation(aStr), false);
+      }
+      NS_ENSURE_TRUE(
+          AppendToString(u"<meta http-equiv=\"content-type\""_ns, aStr), false);
+      NS_ENSURE_TRUE(AppendToString(u" content=\"text/html; charset="_ns, aStr),
+                     false);
+      NS_ENSURE_TRUE(AppendToString(NS_ConvertASCIItoUTF16(mCharset), aStr),
+                     false);
+      if (mIsHTMLSerializer) {
+        NS_ENSURE_TRUE(AppendToString(u"\">"_ns, aStr), false);
+      } else {
+        NS_ENSURE_TRUE(AppendToString(u"\" />"_ns, aStr), false);
+      }
+    }
+  }
+
+  return true;
+}
+
+void nsXHTMLContentSerializer::AfterElementEnd(nsIContent* aContent,
+                                               nsAString& aStr) {
+  NS_ASSERTION(!mIsHTMLSerializer,
+               "nsHTMLContentSerializer shouldn't call this method !");
+
+  // this method is not called by nsHTMLContentSerializer
+  // so we don't have to check HTML element, just XHTML
+  if (aContent->IsHTMLElement(nsGkAtoms::body)) {
+    --mInBody;
+  }
+}
+
+NS_IMETHODIMP
+nsXHTMLContentSerializer::AppendDocumentStart(Document* aDocument) {
+  if (!mBodyOnly) {
+    return nsXMLContentSerializer::AppendDocumentStart(aDocument);
+  }
+
+  return NS_OK;
+}
+
+bool nsXHTMLContentSerializer::CheckElementStart(Element* aElement,
+                                                 bool& aForceFormat,
+                                                 nsAString& aStr,
+                                                 nsresult& aResult) {
+  aResult = NS_OK;
+
+  // The _moz_dirty attribute is emitted by the editor to
+  // indicate that this element should be pretty printed
+  // even if we're not in pretty printing mode
+  aForceFormat = !(mFlags & nsIDocumentEncoder::OutputIgnoreMozDirty) &&
+                 aElement->HasAttr(kNameSpaceID_None, nsGkAtoms::mozdirty);
+
+  if (aElement->IsHTMLElement(nsGkAtoms::br) &&
+      (mFlags & nsIDocumentEncoder::OutputNoFormattingInPre) &&
+      PreLevel() > 0) {
+    aResult = AppendNewLineToString(aStr) ? NS_OK : NS_ERROR_OUT_OF_MEMORY;
+    return false;
+  }
+
+  if (aElement->IsHTMLElement(nsGkAtoms::body)) {
+    ++mInBody;
+  }
+
+  return true;
+}
+
+bool nsXHTMLContentSerializer::CheckElementEnd(Element* aElement,
+                                               Element* aOriginalElement,
+                                               bool& aForceFormat,
+                                               nsAString& aStr) {
+  NS_ASSERTION(!mIsHTMLSerializer,
+               "nsHTMLContentSerializer shouldn't call this method !");
+
+  aForceFormat = !(mFlags & nsIDocumentEncoder::OutputIgnoreMozDirty) &&
+                 aElement->HasAttr(kNameSpaceID_None, nsGkAtoms::mozdirty);
+
+  if (mIsCopying && aElement->IsHTMLElement(nsGkAtoms::ol)) {
+    NS_ASSERTION((!mOLStateStack.IsEmpty()), "Cannot have an empty OL Stack");
+    /* Though at this point we must always have an state to be deleted as all
+       the OL opening tags are supposed to push an olState object to the stack*/
+    if (!mOLStateStack.IsEmpty()) {
+      mOLStateStack.RemoveLastElement();
+    }
+  }
+
+  bool dummyFormat;
+  return nsXMLContentSerializer::CheckElementEnd(aElement, aOriginalElement,
+                                                 dummyFormat, aStr);
+}
+
+bool nsXHTMLContentSerializer::AppendAndTranslateEntities(
+    const nsAString& aStr, nsAString& aOutputStr) {
+  if (mBodyOnly && !mInBody) {
+    return true;
+  }
+
+  if (mDisableEntityEncoding) {
+    return aOutputStr.Append(aStr, fallible);
+  }
+
+  return nsXMLContentSerializer::AppendAndTranslateEntities(aStr, aOutputStr);
+}
+
+bool nsXHTMLContentSerializer::IsShorthandAttr(const nsAtom* aAttrName,
+                                               const nsAtom* aElementName) {
+  // checked
+  if ((aAttrName == nsGkAtoms::checked) && (aElementName == nsGkAtoms::input)) {
+    return true;
+  }
+
+  // compact
+  if ((aAttrName == nsGkAtoms::compact) &&
+      (aElementName == nsGkAtoms::dir || aElementName == nsGkAtoms::dl ||
+       aElementName == nsGkAtoms::menu || aElementName == nsGkAtoms::ol ||
+       aElementName == nsGkAtoms::ul)) {
+    return true;
+  }
+
+  // declare
+  if ((aAttrName == nsGkAtoms::declare) &&
+      (aElementName == nsGkAtoms::object)) {
+    return true;
+  }
+
+  // defer
+  if ((aAttrName == nsGkAtoms::defer) && (aElementName == nsGkAtoms::script)) {
+    return true;
+  }
+
+  // disabled
+  if ((aAttrName == nsGkAtoms::disabled) &&
+      (aElementName == nsGkAtoms::button || aElementName == nsGkAtoms::input ||
+       aElementName == nsGkAtoms::optgroup ||
+       aElementName == nsGkAtoms::option || aElementName == nsGkAtoms::select ||
+       aElementName == nsGkAtoms::textarea)) {
+    return true;
+  }
+
+  // ismap
+  if ((aAttrName == nsGkAtoms::ismap) &&
+      (aElementName == nsGkAtoms::img || aElementName == nsGkAtoms::input)) {
+    return true;
+  }
+
+  // multiple
+  if ((aAttrName == nsGkAtoms::multiple) &&
+      (aElementName == nsGkAtoms::select)) {
+    return true;
+  }
+
+  // noresize
+  if ((aAttrName == nsGkAtoms::noresize) &&
+      (aElementName == nsGkAtoms::frame)) {
+    return true;
+  }
+
+  // noshade
+  if ((aAttrName == nsGkAtoms::noshade) && (aElementName == nsGkAtoms::hr)) {
+    return true;
+  }
+
+  // nowrap
+  if ((aAttrName == nsGkAtoms::nowrap) &&
+      (aElementName == nsGkAtoms::td || aElementName == nsGkAtoms::th)) {
+    return true;
+  }
+
+  // readonly
+  if ((aAttrName == nsGkAtoms::readonly) &&
+      (aElementName == nsGkAtoms::input ||
+       aElementName == nsGkAtoms::textarea)) {
+    return true;
+  }
+
+  // selected
+  if ((aAttrName == nsGkAtoms::selected) &&
+      (aElementName == nsGkAtoms::option)) {
+    return true;
+  }
+
+  // autoplay and controls
+  if ((aElementName == nsGkAtoms::video || aElementName == nsGkAtoms::audio) &&
+      (aAttrName == nsGkAtoms::autoplay || aAttrName == nsGkAtoms::muted ||
+       aAttrName == nsGkAtoms::controls)) {
+    return true;
+  }
+
+  return false;
+}
+
+bool nsXHTMLContentSerializer::LineBreakBeforeOpen(int32_t aNamespaceID,
+                                                   nsAtom* aName) {
+  if (aNamespaceID != kNameSpaceID_XHTML) {
+    return mAddSpace;
+  }
+
+  if (aName == nsGkAtoms::title || aName == nsGkAtoms::meta ||
+      aName == nsGkAtoms::link || aName == nsGkAtoms::style ||
+      aName == nsGkAtoms::select || aName == nsGkAtoms::option ||
+      aName == nsGkAtoms::script || aName == nsGkAtoms::html) {
+    return true;
+  }
+
+  return nsHTMLElement::IsBlock(nsHTMLTags::CaseSensitiveAtomTagToId(aName));
+}
+
+bool nsXHTMLContentSerializer::LineBreakAfterOpen(int32_t aNamespaceID,
+                                                  nsAtom* aName) {
+  if (aNamespaceID != kNameSpaceID_XHTML) {
+    return false;
+  }
+
+  if ((aName == nsGkAtoms::html) || (aName == nsGkAtoms::head) ||
+      (aName == nsGkAtoms::body) || (aName == nsGkAtoms::ul) ||
+      (aName == nsGkAtoms::ol) || (aName == nsGkAtoms::dl) ||
+      (aName == nsGkAtoms::table) || (aName == nsGkAtoms::tbody) ||
+      (aName == nsGkAtoms::tr) || (aName == nsGkAtoms::br) ||
+      (aName == nsGkAtoms::meta) || (aName == nsGkAtoms::link) ||
+      (aName == nsGkAtoms::script) || (aName == nsGkAtoms::select) ||
+      (aName == nsGkAtoms::map) || (aName == nsGkAtoms::area) ||
+      (aName == nsGkAtoms::style)) {
+    return true;
+  }
+
+  return false;
+}
+
+bool nsXHTMLContentSerializer::LineBreakBeforeClose(int32_t aNamespaceID,
+                                                    nsAtom* aName) {
+  if (aNamespaceID != kNameSpaceID_XHTML) {
+    return false;
+  }
+
+  if ((aName == nsGkAtoms::html) || (aName == nsGkAtoms::head) ||
+      (aName == nsGkAtoms::body) || (aName == nsGkAtoms::ul) ||
+      (aName == nsGkAtoms::ol) || (aName == nsGkAtoms::dl) ||
+      (aName == nsGkAtoms::select) || (aName == nsGkAtoms::table) ||
+      (aName == nsGkAtoms::tbody)) {
+    return true;
+  }
+  return false;
+}
+
+bool nsXHTMLContentSerializer::LineBreakAfterClose(int32_t aNamespaceID,
+                                                   nsAtom* aName) {
+  if (aNamespaceID != kNameSpaceID_XHTML) {
+    return false;
+  }
+
+  if ((aName == nsGkAtoms::html) || (aName == nsGkAtoms::head) ||
+      (aName == nsGkAtoms::body) || (aName == nsGkAtoms::tr) ||
+      (aName == nsGkAtoms::th) || (aName == nsGkAtoms::td) ||
+      (aName == nsGkAtoms::title) || (aName == nsGkAtoms::dt) ||
+      (aName == nsGkAtoms::dd) || (aName == nsGkAtoms::select) ||
+      (aName == nsGkAtoms::option) || (aName == nsGkAtoms::map)) {
+    return true;
+  }
+
+  return nsHTMLElement::IsBlock(nsHTMLTags::CaseSensitiveAtomTagToId(aName));
+}
+
+void nsXHTMLContentSerializer::MaybeEnterInPreContent(nsIContent* aNode) {
+  if (!ShouldMaintainPreLevel() || !aNode->IsHTMLElement()) {
+    return;
+  }
+
+  if (IsElementPreformatted(aNode) ||
+      aNode->IsAnyOfHTMLElements(nsGkAtoms::script, nsGkAtoms::style,
+                                 nsGkAtoms::noscript, nsGkAtoms::noframes)) {
+    PreLevel()++;
+  }
+}
+
+void nsXHTMLContentSerializer::MaybeLeaveFromPreContent(nsIContent* aNode) {
+  if (!ShouldMaintainPreLevel() || !aNode->IsHTMLElement()) {
+    return;
+  }
+
+  if (IsElementPreformatted(aNode) ||
+      aNode->IsAnyOfHTMLElements(nsGkAtoms::script, nsGkAtoms::style,
+                                 nsGkAtoms::noscript, nsGkAtoms::noframes)) {
+    --PreLevel();
+  }
+}
+
+bool nsXHTMLContentSerializer::IsElementPreformatted(nsIContent* aNode) {
+  MOZ_ASSERT(ShouldMaintainPreLevel(),
+             "We should not be calling this needlessly");
+
+  if (!aNode->IsElement()) {
+    return false;
+  }
+  RefPtr<ComputedStyle> computedStyle =
+      nsComputedDOMStyle::GetComputedStyleNoFlush(aNode->AsElement(), nullptr);
+  if (computedStyle) {
+    const nsStyleText* textStyle = computedStyle->StyleText();
+    return textStyle->WhiteSpaceOrNewlineIsSignificant();
+  }
+  return false;
+}
+
+bool nsXHTMLContentSerializer::SerializeLIValueAttribute(nsIContent* aElement,
+                                                         nsAString& aStr) {
+  // We are copying and we are at the "first" LI node of OL in selected range.
+  // It may not be the first LI child of OL but it's first in the selected
+  // range. Note that we get into this condition only once per a OL.
+  bool found = false;
+  nsAutoString valueStr;
+
+  olState state(0, false);
+
+  if (!mOLStateStack.IsEmpty()) {
+    state = mOLStateStack[mOLStateStack.Length() - 1];
+    // isFirstListItem should be true only before the serialization of the
+    // first item in the list.
+    state.isFirstListItem = false;
+    mOLStateStack[mOLStateStack.Length() - 1] = state;
+  }
+
+  int32_t startVal = state.startVal;
+  int32_t offset = 0;
+
+  // Traverse previous siblings until we find one with "value" attribute.
+  // offset keeps track of how many previous siblings we had to traverse.
+  nsIContent* currNode = aElement;
+  while (currNode && !found) {
+    if (currNode->IsHTMLElement(nsGkAtoms::li)) {
+      currNode->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::value,
+                                     valueStr);
+      if (valueStr.IsEmpty()) {
+        offset++;
+      } else {
+        found = true;
+        nsresult rv = NS_OK;
+        startVal = valueStr.ToInteger(&rv);
+      }
+    }
+    currNode = currNode->GetPreviousSibling();
+  }
+  // If LI was not having "value", Set the "value" attribute for it.
+  // Note that We are at the first LI in the selected range of OL.
+  if (offset == 0 && found) {
+    // offset = 0 => LI itself has the value attribute and we did not need to
+    // traverse back. Just serialize value attribute like other tags.
+    NS_ENSURE_TRUE(SerializeAttr(u""_ns, u"value"_ns, valueStr, aStr, false),
+                   false);
+  } else if (offset == 1 && !found) {
+    /*(offset = 1 && !found) means either LI is the first child node of OL
+    and LI is not having "value" attribute.
+    In that case we would not like to set "value" attribute to reduce the
+    changes.
+    */
+    // do nothing...
+  } else if (offset > 0) {
+    // Set value attribute.
+    nsAutoString valueStr;
+
+    // As serializer needs to use this valueAttr we are creating here,
+    valueStr.AppendInt(startVal + offset);
+    NS_ENSURE_TRUE(SerializeAttr(u""_ns, u"value"_ns, valueStr, aStr, false),
+                   false);
+  }
+
+  return true;
+}
+
+bool nsXHTMLContentSerializer::IsFirstChildOfOL(nsIContent* aElement) {
+  nsIContent* parent = aElement->GetParent();
+  if (parent && parent->NodeName().LowerCaseEqualsLiteral("ol")) {
+    if (!mOLStateStack.IsEmpty()) {
+      olState state = mOLStateStack[mOLStateStack.Length() - 1];
+      if (state.isFirstListItem) return true;
+    }
+  }
+
+  return false;
+}
+
+bool nsXHTMLContentSerializer::HasNoChildren(nsIContent* aContent) {
+  for (nsIContent* child = aContent->GetFirstChild(); child;
+       child = child->GetNextSibling()) {
+    if (!child->IsText()) return false;
+
+    if (child->TextLength()) return false;
+  }
+
+  return true;
+}