18 files changed, 1455 insertions, 0 deletions
diff --git a/dom/xslt/base/moz.build b/dom/xslt/base/moz.build
new file mode 100644
index 0000000000..1b22391983
--- /dev/null
+++ b/dom/xslt/base/moz.build
@@ -0,0 +1,23 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+UNIFIED_SOURCES += [
+    "txDouble.cpp",
+    "txExpandedName.cpp",
+    "txExpandedNameMap.cpp",
+    "txList.cpp",
+    "txNamespaceMap.cpp",
+    "txURIUtils.cpp",
+]
+
+LOCAL_INCLUDES += [
+    "..",
+    "../xml",
+    "../xpath",
+    "../xslt",
+]
+
+FINAL_LIBRARY = "xul"
diff --git a/dom/xslt/base/txCore.h b/dom/xslt/base/txCore.h
new file mode 100644
index 0000000000..6e462a5a31
--- /dev/null
+++ b/dom/xslt/base/txCore.h
@@ -0,0 +1,42 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef __txCore_h__
+#define __txCore_h__
+
+#include "nscore.h"
+#include "nsDebug.h"
+#include "nsISupportsImpl.h"
+#include "nsStringFwd.h"
+
+class txObject {
+ public:
+  MOZ_COUNTED_DEFAULT_CTOR(txObject)
+
+  /**
+   * Deletes this txObject
+   */
+  MOZ_COUNTED_DTOR_VIRTUAL(txObject)
+};
+
+/**
+ * Utility class for doubles
+ */
+class txDouble {
+ public:
+  /**
+   * Converts the value of the given double to a string, and appends
+   * the result to the destination string.
+   */
+  static void toString(double aValue, nsAString& aDest);
+
+  /**
+   * Converts the given String to a double, if the string value does not
+   * represent a double, NaN will be returned.
+   */
+  static double toDouble(const nsAString& aStr);
+};
+
+#endif
diff --git a/dom/xslt/base/txDouble.cpp b/dom/xslt/base/txDouble.cpp
new file mode 100644
index 0000000000..ad7fa690be
--- /dev/null
+++ b/dom/xslt/base/txDouble.cpp
@@ -0,0 +1,194 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "mozilla/FloatingPoint.h"
+
+#include "nsString.h"
+#include "txCore.h"
+#include "txXMLUtils.h"
+#include <math.h>
+#include <stdlib.h>
+#include <algorithm>
+#ifdef WIN32
+#  include <float.h>
+#endif
+#include "prdtoa.h"
+
+/*
+ * Utility class for doubles
+ */
+
+/*
+ * Converts the given String to a double, if the String value does not
+ * represent a double, NaN will be returned
+ */
+class txStringToDouble {
+ public:
+  txStringToDouble() : mState(eWhitestart), mSign(ePositive) {}
+
+  void Parse(const nsAString& aSource) {
+    if (mState == eIllegal) {
+      return;
+    }
+    uint32_t i = 0;
+    char16_t c;
+    auto len = aSource.Length();
+    for (; i < len; ++i) {
+      c = aSource[i];
+      switch (mState) {
+        case eWhitestart:
+          if (c == '-') {
+            mState = eDecimal;
+            mSign = eNegative;
+          } else if (c >= '0' && c <= '9') {
+            mState = eDecimal;
+            mBuffer.Append((char)c);
+          } else if (c == '.') {
+            mState = eMantissa;
+            mBuffer.Append((char)c);
+          } else if (!XMLUtils::isWhitespace(c)) {
+            mState = eIllegal;
+            return;
+          }
+          break;
+        case eDecimal:
+          if (c >= '0' && c <= '9') {
+            mBuffer.Append((char)c);
+          } else if (c == '.') {
+            mState = eMantissa;
+            mBuffer.Append((char)c);
+          } else if (XMLUtils::isWhitespace(c)) {
+            mState = eWhiteend;
+          } else {
+            mState = eIllegal;
+            return;
+          }
+          break;
+        case eMantissa:
+          if (c >= '0' && c <= '9') {
+            mBuffer.Append((char)c);
+          } else if (XMLUtils::isWhitespace(c)) {
+            mState = eWhiteend;
+          } else {
+            mState = eIllegal;
+            return;
+          }
+          break;
+        case eWhiteend:
+          if (!XMLUtils::isWhitespace(c)) {
+            mState = eIllegal;
+            return;
+          }
+          break;
+        default:
+          break;
+      }
+    }
+  }
+
+  double getDouble() {
+    if (mState == eIllegal || mBuffer.IsEmpty() ||
+        (mBuffer.Length() == 1 && mBuffer[0] == '.')) {
+      return mozilla::UnspecifiedNaN<double>();
+    }
+    return static_cast<double>(mSign) * PR_strtod(mBuffer.get(), nullptr);
+  }
+
+ private:
+  nsAutoCString mBuffer;
+  enum { eWhitestart, eDecimal, eMantissa, eWhiteend, eIllegal } mState;
+  enum { eNegative = -1, ePositive = 1 } mSign;
+};
+
+double txDouble::toDouble(const nsAString& aSrc) {
+  txStringToDouble sink;
+  sink.Parse(aSrc);
+  return sink.getDouble();
+}
+
+/*
+ * Converts the value of the given double to a String, and places
+ * The result into the destination String.
+ * @return the given dest string
+ */
+void txDouble::toString(double aValue, nsAString& aDest) {
+  // check for special cases
+
+  if (std::isnan(aValue)) {
+    aDest.AppendLiteral("NaN");
+    return;
+  }
+  if (std::isinf(aValue)) {
+    if (aValue < 0) aDest.Append(char16_t('-'));
+    aDest.AppendLiteral("Infinity");
+    return;
+  }
+
+  // Mantissa length is 17, so this is plenty
+  const int buflen = 20;
+  char buf[buflen];
+
+  int intDigits, sign;
+  char* endp;
+  PR_dtoa(aValue, 0, 0, &intDigits, &sign, &endp, buf, buflen - 1);
+
+  // compute length
+  int32_t length = endp - buf;
+  if (length > intDigits) {
+    // decimal point needed
+    ++length;
+    if (intDigits < 1) {
+      // leading zeros, -intDigits + 1
+      length += 1 - intDigits;
+    }
+  } else {
+    // trailing zeros, total length given by intDigits
+    length = intDigits;
+  }
+  if (aValue < 0) ++length;
+  // grow the string
+  uint32_t oldlength = aDest.Length();
+  if (!aDest.SetLength(oldlength + length, mozilla::fallible))
+    return;  // out of memory
+  auto dest = aDest.BeginWriting();
+  std::advance(dest, oldlength);
+  if (aValue < 0) {
+    *dest = '-';
+    ++dest;
+  }
+  int i;
+  // leading zeros
+  if (intDigits < 1) {
+    *dest = '0';
+    ++dest;
+    *dest = '.';
+    ++dest;
+    for (i = 0; i > intDigits; --i) {
+      *dest = '0';
+      ++dest;
+    }
+  }
+  // mantissa
+  int firstlen = std::min<size_t>(intDigits, endp - buf);
+  for (i = 0; i < firstlen; i++) {
+    *dest = buf[i];
+    ++dest;
+  }
+  if (i < endp - buf) {
+    if (i > 0) {
+      *dest = '.';
+      ++dest;
+    }
+    for (; i < endp - buf; i++) {
+      *dest = buf[i];
+      ++dest;
+    }
+  }
+  // trailing zeros
+  for (; i < intDigits; i++) {
+    *dest = '0';
+    ++dest;
+  }
+}
diff --git a/dom/xslt/base/txErrorObserver.h b/dom/xslt/base/txErrorObserver.h
new file mode 100644
index 0000000000..30b541f2a9
--- /dev/null
+++ b/dom/xslt/base/txErrorObserver.h
@@ -0,0 +1,36 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef MITRE_ERROROBSERVER_H
+#define MITRE_ERROROBSERVER_H
+
+#include "txCore.h"
+
+/**
+ * A simple interface for observing errors
+ **/
+class ErrorObserver {
+ public:
+  /**
+   * Default Destructor for ErrorObserver
+   **/
+  virtual ~ErrorObserver(){};
+
+  /**
+   *  Notifies this Error observer of a new error aRes
+   **/
+  virtual void receiveError(const nsAString& errorMessage, nsresult aRes) = 0;
+
+  /**
+   *  Notifies this Error observer of a new error, with default
+   *  error code NS_ERROR_FAILURE
+   **/
+  void receiveError(const nsAString& errorMessage) {
+    receiveError(errorMessage, NS_ERROR_FAILURE);
+  }
+
+};  //-- ErrorObserver
+
+#endif
diff --git a/dom/xslt/base/txExpandedName.cpp b/dom/xslt/base/txExpandedName.cpp
new file mode 100644
index 0000000000..af11476056
--- /dev/null
+++ b/dom/xslt/base/txExpandedName.cpp
@@ -0,0 +1,37 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "txExpandedName.h"
+#include "nsString.h"
+#include "nsReadableUtils.h"
+#include "txStringUtils.h"
+#include "txNamespaceMap.h"
+#include "txXMLUtils.h"
+
+nsresult txExpandedName::init(const nsAString& aQName,
+                              txNamespaceMap* aResolver, bool aUseDefault) {
+  const nsString& qName = PromiseFlatString(aQName);
+  const char16_t* colon;
+  bool valid = XMLUtils::isValidQName(qName, &colon);
+  if (!valid) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (colon) {
+    RefPtr<nsAtom> prefix = NS_Atomize(Substring(qName.get(), colon));
+    int32_t namespaceID = aResolver->lookupNamespace(prefix);
+    if (namespaceID == kNameSpaceID_Unknown) return NS_ERROR_FAILURE;
+    mNamespaceID = namespaceID;
+
+    const char16_t* end;
+    qName.EndReading(end);
+    mLocalName = NS_Atomize(Substring(colon + 1, end));
+  } else {
+    mNamespaceID =
+        aUseDefault ? aResolver->lookupNamespace(nullptr) : kNameSpaceID_None;
+    mLocalName = NS_Atomize(aQName);
+  }
+  return NS_OK;
+}
diff --git a/dom/xslt/base/txExpandedName.h b/dom/xslt/base/txExpandedName.h
new file mode 100644
index 0000000000..76d82a8eee
--- /dev/null
+++ b/dom/xslt/base/txExpandedName.h
@@ -0,0 +1,50 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef TRANSFRMX_EXPANDEDNAME_H
+#define TRANSFRMX_EXPANDEDNAME_H
+
+#include "nsCOMPtr.h"
+#include "nsAtom.h"
+#include "mozilla/dom/NameSpaceConstants.h"
+
+class txNamespaceMap;
+
+class txExpandedName {
+ public:
+  txExpandedName() : mNamespaceID(kNameSpaceID_None) {}
+
+  txExpandedName(int32_t aNsID, nsAtom* aLocalName)
+      : mNamespaceID(aNsID), mLocalName(aLocalName) {}
+
+  txExpandedName(const txExpandedName& aOther) = default;
+
+  nsresult init(const nsAString& aQName, txNamespaceMap* aResolver,
+                bool aUseDefault);
+
+  void reset() {
+    mNamespaceID = kNameSpaceID_None;
+    mLocalName = nullptr;
+  }
+
+  bool isNull() { return mNamespaceID == kNameSpaceID_None && !mLocalName; }
+
+  txExpandedName& operator=(const txExpandedName& rhs) = default;
+
+  bool operator==(const txExpandedName& rhs) const {
+    return ((mLocalName == rhs.mLocalName) &&
+            (mNamespaceID == rhs.mNamespaceID));
+  }
+
+  bool operator!=(const txExpandedName& rhs) const {
+    return ((mLocalName != rhs.mLocalName) ||
+            (mNamespaceID != rhs.mNamespaceID));
+  }
+
+  int32_t mNamespaceID;
+  RefPtr<nsAtom> mLocalName;
+};
+
+#endif
diff --git a/dom/xslt/base/txExpandedNameMap.cpp b/dom/xslt/base/txExpandedNameMap.cpp
new file mode 100644
index 0000000000..996799abf0
--- /dev/null
+++ b/dom/xslt/base/txExpandedNameMap.cpp
@@ -0,0 +1,94 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "txExpandedNameMap.h"
+#include "txCore.h"
+
+class txMapItemComparator {
+ public:
+  bool Equals(const txExpandedNameMap_base::MapItem& aItem,
+              const txExpandedName& aKey) const {
+    return aItem.mNamespaceID == aKey.mNamespaceID &&
+           aItem.mLocalName == aKey.mLocalName;
+  }
+};
+
+/**
+ * Adds an item, if an item with this key already exists an error is
+ * returned
+ * @param  aKey   key for item to add
+ * @param  aValue value of item to add
+ * @return errorcode
+ */
+nsresult txExpandedNameMap_base::addItem(const txExpandedName& aKey,
+                                         void* aValue) {
+  size_t pos = mItems.IndexOf(aKey, 0, txMapItemComparator());
+  if (pos != mItems.NoIndex) {
+    return NS_ERROR_XSLT_ALREADY_SET;
+  }
+
+  MapItem* item = mItems.AppendElement();
+  item->mNamespaceID = aKey.mNamespaceID;
+  item->mLocalName = aKey.mLocalName;
+  item->mValue = aValue;
+
+  return NS_OK;
+}
+
+/**
+ * Sets an item, if an item with this key already exists it is overwritten
+ * with the new value
+ * @param  aKey   key for item to set
+ * @param  aValue value of item to set
+ * @return errorcode
+ */
+nsresult txExpandedNameMap_base::setItem(const txExpandedName& aKey,
+                                         void* aValue, void** aOldValue) {
+  *aOldValue = nullptr;
+  size_t pos = mItems.IndexOf(aKey, 0, txMapItemComparator());
+  if (pos != mItems.NoIndex) {
+    *aOldValue = mItems[pos].mValue;
+    mItems[pos].mValue = aValue;
+    return NS_OK;
+  }
+
+  MapItem* item = mItems.AppendElement();
+  item->mNamespaceID = aKey.mNamespaceID;
+  item->mLocalName = aKey.mLocalName;
+  item->mValue = aValue;
+
+  return NS_OK;
+}
+
+/**
+ * Gets an item
+ * @param  aKey  key for item to get
+ * @return item with specified key, or null if no such item exists
+ */
+void* txExpandedNameMap_base::getItem(const txExpandedName& aKey) const {
+  size_t pos = mItems.IndexOf(aKey, 0, txMapItemComparator());
+  if (pos != mItems.NoIndex) {
+    return mItems[pos].mValue;
+  }
+
+  return nullptr;
+}
+
+/**
+ * Removes an item, deleting it if the map owns the values
+ * @param  aKey  key for item to remove
+ * @return item with specified key, or null if it has been deleted
+ *         or no such item exists
+ */
+void* txExpandedNameMap_base::removeItem(const txExpandedName& aKey) {
+  void* value = nullptr;
+  size_t pos = mItems.IndexOf(aKey, 0, txMapItemComparator());
+  if (pos != mItems.NoIndex) {
+    value = mItems[pos].mValue;
+    mItems.RemoveElementAt(pos);
+  }
+
+  return value;
+}
diff --git a/dom/xslt/base/txExpandedNameMap.h b/dom/xslt/base/txExpandedNameMap.h
new file mode 100644
index 0000000000..6e308a65f8
--- /dev/null
+++ b/dom/xslt/base/txExpandedNameMap.h
@@ -0,0 +1,153 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef TRANSFRMX_EXPANDEDNAMEMAP_H
+#define TRANSFRMX_EXPANDEDNAMEMAP_H
+
+#include "mozilla/UniquePtr.h"
+#include "mozilla/UniquePtrExtensions.h"
+#include "nsError.h"
+#include "txExpandedName.h"
+#include "nsTArray.h"
+
+class txExpandedNameMap_base {
+ protected:
+  /**
+   * Adds an item, if an item with this key already exists an error is
+   * returned
+   * @param  aKey   key for item to add
+   * @param  aValue value of item to add
+   * @return errorcode
+   */
+  nsresult addItem(const txExpandedName& aKey, void* aValue);
+
+  /**
+   * Sets an item, if an item with this key already exists it is overwritten
+   * with the new value
+   * @param  aKey   key for item to set
+   * @param  aValue value of item to set
+   * @return errorcode
+   */
+  nsresult setItem(const txExpandedName& aKey, void* aValue, void** aOldValue);
+
+  /**
+   * Gets an item
+   * @param  aKey  key for item to get
+   * @return item with specified key, or null if no such item exists
+   */
+  void* getItem(const txExpandedName& aKey) const;
+
+  /**
+   * Removes an item, deleting it if the map owns the values
+   * @param  aKey  key for item to remove
+   * @return item with specified key, or null if it has been deleted
+   *         or no such item exists
+   */
+  void* removeItem(const txExpandedName& aKey);
+
+  /**
+   * Clears the items
+   */
+  void clearItems() { mItems.Clear(); }
+
+  class iterator_base {
+   public:
+    explicit iterator_base(txExpandedNameMap_base& aMap)
+        : mMap(aMap), mCurrentPos(uint32_t(-1)) {}
+
+    bool next() { return ++mCurrentPos < mMap.mItems.Length(); }
+
+    const txExpandedName key() {
+      NS_ASSERTION(mCurrentPos < mMap.mItems.Length(),
+                   "invalid position in txExpandedNameMap::iterator");
+      return txExpandedName(mMap.mItems[mCurrentPos].mNamespaceID,
+                            mMap.mItems[mCurrentPos].mLocalName);
+    }
+
+   protected:
+    void* itemValue() {
+      NS_ASSERTION(mCurrentPos < mMap.mItems.Length(),
+                   "invalid position in txExpandedNameMap::iterator");
+      return mMap.mItems[mCurrentPos].mValue;
+    }
+
+   private:
+    txExpandedNameMap_base& mMap;
+    uint32_t mCurrentPos;
+  };
+
+  friend class iterator_base;
+
+  friend class txMapItemComparator;
+  struct MapItem {
+    int32_t mNamespaceID;
+    RefPtr<nsAtom> mLocalName;
+    void* mValue;
+  };
+
+  nsTArray<MapItem> mItems;
+};
+
+template <class E>
+class txExpandedNameMap : public txExpandedNameMap_base {
+ public:
+  nsresult add(const txExpandedName& aKey, E* aValue) {
+    return addItem(aKey, (void*)aValue);
+  }
+
+  nsresult set(const txExpandedName& aKey, E* aValue) {
+    void* oldValue;
+    return setItem(aKey, (void*)aValue, &oldValue);
+  }
+
+  E* get(const txExpandedName& aKey) const { return (E*)getItem(aKey); }
+
+  E* remove(const txExpandedName& aKey) { return (E*)removeItem(aKey); }
+
+  void clear() { clearItems(); }
+
+  class iterator : public iterator_base {
+   public:
+    explicit iterator(txExpandedNameMap& aMap) : iterator_base(aMap) {}
+
+    E* value() { return (E*)itemValue(); }
+  };
+};
+
+template <class E>
+class txOwningExpandedNameMap : public txExpandedNameMap_base {
+ public:
+  ~txOwningExpandedNameMap() { clear(); }
+
+  nsresult add(const txExpandedName& aKey, E* aValue) {
+    return addItem(aKey, (void*)aValue);
+  }
+
+  nsresult set(const txExpandedName& aKey, E* aValue) {
+    mozilla::UniquePtr<E> oldValue;
+    return setItem(aKey, (void*)aValue, getter_Transfers(oldValue));
+  }
+
+  E* get(const txExpandedName& aKey) const { return (E*)getItem(aKey); }
+
+  void remove(const txExpandedName& aKey) { delete (E*)removeItem(aKey); }
+
+  void clear() {
+    uint32_t i, len = mItems.Length();
+    for (i = 0; i < len; ++i) {
+      delete (E*)mItems[i].mValue;
+    }
+    clearItems();
+  }
+
+  class iterator : public iterator_base {
+   public:
+    explicit iterator(txOwningExpandedNameMap& aMap) : iterator_base(aMap) {}
+
+    E* value() { return (E*)itemValue(); }
+  };
+};
+
+#endif  // TRANSFRMX_EXPANDEDNAMEMAP_H
diff --git a/dom/xslt/base/txList.cpp b/dom/xslt/base/txList.cpp
new file mode 100644
index 0000000000..a361490784
--- /dev/null
+++ b/dom/xslt/base/txList.cpp
@@ -0,0 +1,249 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "txList.h"
+
+//----------------------------/
+//- Implementation of txList -/
+//----------------------------/
+
+/**
+ * Default constructor for a txList;
+ **/
+
+txList::txList() {
+  firstItem = 0;
+  lastItem = 0;
+  itemCount = 0;
+}  //-- txList;
+
+/**
+ * txList destructor, cleans up ListItems, but will not delete the Object
+ * references
+ */
+txList::~txList() { clear(); }  //-- ~txList
+
+void txList::add(void* objPtr) { insertBefore(objPtr, nullptr); }  //-- add
+
+/**
+ * Returns the number of items in this txList
+ **/
+int32_t List::getLength() { return itemCount; }  //-- getLength
+
+/**
+ * Inserts the given Object pointer as the item just after refItem.
+ * If refItem is a null pointer the Object will be inserted at the
+ * beginning of the txList (ie, insert after nothing).
+ * This method assumes refItem is a member of this list, and since this
+ * is a private method, I feel that's a valid assumption
+ **/
+void txList::insertAfter(void* objPtr, ListItem* refItem) {
+  insertBefore(objPtr, refItem ? refItem->nextItem : firstItem);
+}  //-- insertAfter
+
+/**
+ * Inserts the given Object pointer as the item just before refItem.
+ * If refItem is a null pointer the Object will be inserted at the
+ * end of the txList (ie, insert before nothing).
+ * This method assumes refItem is a member of this list, and since this
+ * is a private method, I feel that's a valid assumption
+ **/
+void txList::insertBefore(void* objPtr, ListItem* refItem) {
+  ListItem* item = new ListItem;
+  item->objPtr = objPtr;
+  item->nextItem = 0;
+  item->prevItem = 0;
+
+  //-- if refItem == null insert at end
+  if (!refItem) {
+    //-- add to back of list
+    if (lastItem) {
+      lastItem->nextItem = item;
+      item->prevItem = lastItem;
+    }
+    lastItem = item;
+    if (!firstItem) firstItem = item;
+  } else {
+    //-- insert before given item
+    item->nextItem = refItem;
+    item->prevItem = refItem->prevItem;
+    refItem->prevItem = item;
+
+    if (item->prevItem)
+      item->prevItem->nextItem = item;
+    else
+      firstItem = item;
+  }
+
+  // increase the item count
+  ++itemCount;
+}  //-- insertBefore
+
+txList::ListItem* txList::remove(ListItem* item) {
+  if (!item) return item;
+
+  //-- adjust the previous item's next pointer
+  if (item->prevItem) {
+    item->prevItem->nextItem = item->nextItem;
+  }
+  //-- adjust the next item's previous pointer
+  if (item->nextItem) {
+    item->nextItem->prevItem = item->prevItem;
+  }
+
+  //-- adjust first and last items
+  if (item == firstItem) firstItem = item->nextItem;
+  if (item == lastItem) lastItem = item->prevItem;
+
+  //-- decrease Item count
+  --itemCount;
+  return item;
+}  //-- remove
+
+void txList::clear() {
+  ListItem* item = firstItem;
+  while (item) {
+    ListItem* tItem = item;
+    item = item->nextItem;
+    delete tItem;
+  }
+  firstItem = 0;
+  lastItem = 0;
+  itemCount = 0;
+}
+
+//------------------------------------/
+//- Implementation of txListIterator -/
+//------------------------------------/
+
+/**
+ * Creates a new txListIterator for the given txList
+ * @param list, the txList to create an Iterator for
+ **/
+txListIterator::txListIterator(txList* list) {
+  this->list = list;
+  currentItem = 0;
+  atEndOfList = false;
+}  //-- txListIterator
+
+/**
+ * Adds the Object pointer to the txList pointed to by this txListIterator.
+ * The Object pointer is inserted as the next item in the txList
+ * based on the current position within the txList
+ * @param objPtr the Object pointer to add to the list
+ **/
+void txListIterator::addAfter(void* objPtr) {
+  if (currentItem || !atEndOfList) {
+    list->insertAfter(objPtr, currentItem);
+  } else {
+    list->insertBefore(objPtr, nullptr);
+  }
+}  //-- addAfter
+
+/**
+ * Adds the Object pointer to the txList pointed to by this txListIterator.
+ * The Object pointer is inserted as the previous item in the txList
+ * based on the current position within the txList
+ * @param objPtr the Object pointer to add to the list
+ **/
+void txListIterator::addBefore(void* objPtr) {
+  if (currentItem || atEndOfList) {
+    list->insertBefore(objPtr, currentItem);
+  } else {
+    list->insertAfter(objPtr, nullptr);
+  }
+}  //-- addBefore
+
+/**
+ * Returns true if a successful call to the next() method can be made
+ * @return true if a successful call to the next() method can be made,
+ * otherwise false
+ **/
+bool txListIterator::hasNext() {
+  bool hasNext = false;
+  if (currentItem)
+    hasNext = (currentItem->nextItem != 0);
+  else if (!atEndOfList)
+    hasNext = (list->firstItem != 0);
+
+  return hasNext;
+}  //-- hasNext
+
+/**
+ * Returns the next Object pointer in the list
+ **/
+void* txListIterator::next() {
+  void* obj = 0;
+  if (currentItem)
+    currentItem = currentItem->nextItem;
+  else if (!atEndOfList)
+    currentItem = list->firstItem;
+
+  if (currentItem)
+    obj = currentItem->objPtr;
+  else
+    atEndOfList = true;
+
+  return obj;
+}  //-- next
+
+/**
+ * Returns the previous Object in the list
+ **/
+void* txListIterator::previous() {
+  void* obj = 0;
+
+  if (currentItem)
+    currentItem = currentItem->prevItem;
+  else if (atEndOfList)
+    currentItem = list->lastItem;
+
+  if (currentItem) obj = currentItem->objPtr;
+
+  atEndOfList = false;
+
+  return obj;
+}  //-- previous
+
+/**
+ * Returns the current Object
+ **/
+void* txListIterator::current() {
+  if (currentItem) return currentItem->objPtr;
+
+  return 0;
+}  //-- current
+
+/**
+ * Removes the Object last returned by the next() or previous() methods;
+ * @return the removed Object pointer
+ **/
+void* txListIterator::remove() {
+  void* obj = 0;
+  if (currentItem) {
+    obj = currentItem->objPtr;
+    txList::ListItem* item = currentItem;
+    previous();  //-- make previous item the current item
+    list->remove(item);
+    delete item;
+  }
+  return obj;
+}  //-- remove
+
+/**
+ * Resets the current location within the txList to the beginning of the txList
+ **/
+void txListIterator::reset() {
+  atEndOfList = false;
+  currentItem = 0;
+}  //-- reset
+
+/**
+ * Move the iterator to right after the last element
+ **/
+void txListIterator::resetToEnd() {
+  atEndOfList = true;
+  currentItem = 0;
+}  //-- moveToEnd
diff --git a/dom/xslt/base/txList.h b/dom/xslt/base/txList.h
new file mode 100644
index 0000000000..eeafd12dda
--- /dev/null
+++ b/dom/xslt/base/txList.h
@@ -0,0 +1,152 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef TRANSFRMX_LIST_H
+#define TRANSFRMX_LIST_H
+
+#include "txCore.h"
+
+class txListIterator;
+
+/**
+ * Represents an ordered list of Object pointers. Modeled after a Java 2 List.
+ **/
+class txList : public txObject {
+  friend class txListIterator;
+
+ public:
+  /**
+   * Creates an empty txList
+   **/
+  txList();
+
+  /**
+   * txList destructor, object references will not be deleted.
+   **/
+  ~txList();
+
+  /**
+   * Returns the number of items in this txList
+   **/
+  int32_t getLength();
+
+  /**
+   * Returns true if there are no items in this txList
+   */
+  inline bool isEmpty() { return itemCount == 0; }
+
+  /**
+   * Adds the given Object to the list
+   **/
+  void add(void* objPtr);
+
+  /*
+   * Removes all the objects from the list
+   */
+  void clear();
+
+ protected:
+  struct ListItem {
+    ListItem* nextItem;
+    ListItem* prevItem;
+    void* objPtr;
+  };
+
+  /**
+   * Removes the given ListItem pointer from the list
+   **/
+  ListItem* remove(ListItem* sItem);
+
+ private:
+  txList(const txList& aOther);  // not implemented
+
+  ListItem* firstItem;
+  ListItem* lastItem;
+  int32_t itemCount;
+
+  void insertAfter(void* objPtr, ListItem* sItem);
+  void insertBefore(void* objPtr, ListItem* sItem);
+};
+
+/**
+ * An Iterator for the txList Class
+ **/
+class txListIterator {
+ public:
+  /**
+   * Creates a new txListIterator for the given txList
+   * @param list, the txList to create an Iterator for
+   **/
+  explicit txListIterator(txList* list);
+
+  /**
+   * Adds the Object pointer to the txList pointed to by this txListIterator.
+   * The Object pointer is inserted as the next item in the txList
+   * based on the current position within the txList
+   * @param objPtr the Object pointer to add to the list
+   **/
+  void addAfter(void* objPtr);
+
+  /**
+   * Adds the Object pointer to the txList pointed to by this txListIterator.
+   * The Object pointer is inserted as the previous item in the txList
+   * based on the current position within the txList
+   * @param objPtr the Object pointer to add to the list
+   **/
+  void addBefore(void* objPtr);
+
+  /**
+   * Returns true if a successful call to the next() method can be made
+   * @return true if a successful call to the next() method can be made,
+   * otherwise false
+   **/
+  bool hasNext();
+
+  /**
+   * Returns the next Object pointer from the list
+   **/
+  void* next();
+
+  /**
+   * Returns the previous Object pointer from the list
+   **/
+  void* previous();
+
+  /**
+   * Returns the current Object
+   **/
+  void* current();
+
+  /**
+   * Removes the Object last returned by the next() or previous() methods;
+   * @return the removed Object pointer
+   **/
+  void* remove();
+
+  /**
+   * Resets the current location within the txList to the beginning of the
+   * txList
+   **/
+  void reset();
+
+  /**
+   * Resets the current location within the txList to the end of the txList
+   **/
+  void resetToEnd();
+
+ private:
+  //-- points to the current list item
+  txList::ListItem* currentItem;
+
+  //-- points to the list to iterator over
+  txList* list;
+
+  //-- we've moved off the end of the list
+  bool atEndOfList;
+};
+
+using List = txList;
+
+#endif
diff --git a/dom/xslt/base/txLog.h b/dom/xslt/base/txLog.h
new file mode 100644
index 0000000000..c5b03ca83e
--- /dev/null
+++ b/dom/xslt/base/txLog.h
@@ -0,0 +1,23 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef txLog_h__
+#define txLog_h__
+
+#include "mozilla/Logging.h"
+
+class txLog {
+ public:
+  static mozilla::LazyLogModule xpath;
+  static mozilla::LazyLogModule xslt;
+};
+
+#define TX_LG_IMPL                              \
+  mozilla::LazyLogModule txLog::xpath("xpath"); \
+  mozilla::LazyLogModule txLog::xslt("xslt");
+
+#define TX_LG_CREATE
+
+#endif
diff --git a/dom/xslt/base/txNamespaceMap.cpp b/dom/xslt/base/txNamespaceMap.cpp
new file mode 100644
index 0000000000..284e08a705
--- /dev/null
+++ b/dom/xslt/base/txNamespaceMap.cpp
@@ -0,0 +1,81 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "txNamespaceMap.h"
+#include "nsGkAtoms.h"
+#include "txXPathNode.h"
+
+txNamespaceMap::txNamespaceMap() = default;
+
+txNamespaceMap::txNamespaceMap(const txNamespaceMap& aOther)
+    : mPrefixes(aOther.mPrefixes.Clone()),
+      mNamespaces(aOther.mNamespaces.Clone()) {}
+
+nsresult txNamespaceMap::mapNamespace(nsAtom* aPrefix,
+                                      const nsAString& aNamespaceURI) {
+  nsAtom* prefix = aPrefix == nsGkAtoms::_empty ? nullptr : aPrefix;
+
+  int32_t nsId;
+  if (prefix && aNamespaceURI.IsEmpty()) {
+    // Remove the mapping
+    int32_t index = mPrefixes.IndexOf(prefix);
+    if (index >= 0) {
+      mPrefixes.RemoveElementAt(index);
+      mNamespaces.RemoveElementAt(index);
+    }
+
+    return NS_OK;
+  }
+
+  if (aNamespaceURI.IsEmpty()) {
+    // Set default to empty namespace
+    nsId = kNameSpaceID_None;
+  } else {
+    nsId = txNamespaceManager::getNamespaceID(aNamespaceURI);
+    NS_ENSURE_FALSE(nsId == kNameSpaceID_Unknown, NS_ERROR_FAILURE);
+  }
+
+  // Check if the mapping already exists
+  int32_t index = mPrefixes.IndexOf(prefix);
+  if (index >= 0) {
+    mNamespaces.ElementAt(index) = nsId;
+
+    return NS_OK;
+  }
+
+  // New mapping
+  mPrefixes.AppendElement(prefix);
+  mNamespaces.AppendElement(nsId);
+
+  return NS_OK;
+}
+
+int32_t txNamespaceMap::lookupNamespace(nsAtom* aPrefix) {
+  if (aPrefix == nsGkAtoms::xml) {
+    return kNameSpaceID_XML;
+  }
+
+  nsAtom* prefix = aPrefix == nsGkAtoms::_empty ? 0 : aPrefix;
+
+  int32_t index = mPrefixes.IndexOf(prefix);
+  if (index >= 0) {
+    return mNamespaces.SafeElementAt(index, kNameSpaceID_Unknown);
+  }
+
+  if (!prefix) {
+    return kNameSpaceID_None;
+  }
+
+  return kNameSpaceID_Unknown;
+}
+
+int32_t txNamespaceMap::lookupNamespaceWithDefault(const nsAString& aPrefix) {
+  RefPtr<nsAtom> prefix = NS_Atomize(aPrefix);
+  if (prefix != nsGkAtoms::_poundDefault) {
+    return lookupNamespace(prefix);
+  }
+
+  return lookupNamespace(nullptr);
+}
diff --git a/dom/xslt/base/txNamespaceMap.h b/dom/xslt/base/txNamespaceMap.h
new file mode 100644
index 0000000000..e2be7ebf15
--- /dev/null
+++ b/dom/xslt/base/txNamespaceMap.h
@@ -0,0 +1,38 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef TRANSFRMX_TXNAMESPACEMAP_H
+#define TRANSFRMX_TXNAMESPACEMAP_H
+
+#include "nsAtom.h"
+#include "nsCOMPtr.h"
+#include "nsTArray.h"
+
+class txNamespaceMap {
+ public:
+  txNamespaceMap();
+  txNamespaceMap(const txNamespaceMap& aOther);
+
+  nsrefcnt AddRef() { return ++mRefCnt; }
+  nsrefcnt Release() {
+    if (--mRefCnt == 0) {
+      mRefCnt = 1;  // stabilize
+      delete this;
+      return 0;
+    }
+    return mRefCnt;
+  }
+
+  nsresult mapNamespace(nsAtom* aPrefix, const nsAString& aNamespaceURI);
+  int32_t lookupNamespace(nsAtom* aPrefix);
+  int32_t lookupNamespaceWithDefault(const nsAString& aPrefix);
+
+ private:
+  nsAutoRefCnt mRefCnt;
+  nsTArray<RefPtr<nsAtom>> mPrefixes;
+  nsTArray<int32_t> mNamespaces;
+};
+
+#endif  // TRANSFRMX_TXNAMESPACEMAP_H
diff --git a/dom/xslt/base/txOwningArray.h b/dom/xslt/base/txOwningArray.h
new file mode 100644
index 0000000000..f25015a597
--- /dev/null
+++ b/dom/xslt/base/txOwningArray.h
@@ -0,0 +1,29 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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/. */
+
+#ifndef txOwningArray_h__
+#define txOwningArray_h__
+
+// Class acting like a nsTArray except that it deletes its objects
+// on destruction. It does not however delete its objects on operations
+// like RemoveElementsAt or on |array[i] = bar|.
+
+template <class E>
+class txOwningArray : public nsTArray<E*> {
+ public:
+  typedef nsTArray<E*> base_type;
+  typedef typename base_type::value_type value_type;
+
+  ~txOwningArray() {
+    value_type* iter = base_type::Elements();
+    value_type* end = iter + base_type::Length();
+    for (; iter < end; ++iter) {
+      delete *iter;
+    }
+  }
+};
+
+#endif  // txOwningArray_h__
diff --git a/dom/xslt/base/txStack.h b/dom/xslt/base/txStack.h
new file mode 100644
index 0000000000..9a9269ed69
--- /dev/null
+++ b/dom/xslt/base/txStack.h
@@ -0,0 +1,99 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef txStack_h___
+#define txStack_h___
+
+#include "nsTArray.h"
+
+class txStack : private nsTArray<void*> {
+ public:
+  /**
+   * Returns the specified object from the top of this stack,
+   * without removing it from the stack.
+   *
+   * @return a pointer to the object that is the top of this stack.
+   */
+  inline void* peek() {
+    NS_ASSERTION(!isEmpty(), "peeking at empty stack");
+    return !isEmpty() ? ElementAt(Length() - 1) : nullptr;
+  }
+
+  /**
+   * Adds the specified object to the top of this stack.
+   *
+   * @param obj a pointer to the object that is to be added to the
+   * top of this stack.
+   */
+  inline void push(void* aObject) { AppendElement(aObject); }
+
+  /**
+   * Removes and returns the specified object from the top of this
+   * stack.
+   *
+   * @return a pointer to the object that was the top of this stack.
+   */
+  inline void* pop() {
+    void* object = nullptr;
+    NS_ASSERTION(!isEmpty(), "popping from empty stack");
+    if (!isEmpty()) {
+      object = PopLastElement();
+    }
+    return object;
+  }
+
+  /**
+   * Returns true if there are no objects in the stack.
+   *
+   * @return true if there are no objects in the stack.
+   */
+  inline bool isEmpty() { return IsEmpty(); }
+
+  /**
+   * Returns the number of elements in the Stack.
+   *
+   * @return the number of elements in the Stack.
+   */
+  inline int32_t size() { return Length(); }
+
+ private:
+  friend class txStackIterator;
+};
+
+class txStackIterator {
+ public:
+  /**
+   * Creates an iterator for the given stack.
+   *
+   * @param aStack the stack to create an iterator for.
+   */
+  inline explicit txStackIterator(txStack* aStack)
+      : mStack(aStack), mPosition(0) {}
+
+  /**
+   * Returns true if there is more objects on the stack.
+   *
+   * @return .
+   */
+  inline bool hasNext() { return (mPosition < mStack->Length()); }
+
+  /**
+   * Returns the next object pointer from the stack.
+   *
+   * @return .
+   */
+  inline void* next() {
+    if (mPosition == mStack->Length()) {
+      return nullptr;
+    }
+    return mStack->ElementAt(mPosition++);
+  }
+
+ private:
+  txStack* mStack;
+  uint32_t mPosition;
+};
+
+#endif /* txStack_h___ */
diff --git a/dom/xslt/base/txStringUtils.h b/dom/xslt/base/txStringUtils.h
new file mode 100644
index 0000000000..2064c01720
--- /dev/null
+++ b/dom/xslt/base/txStringUtils.h
@@ -0,0 +1,28 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef txStringUtils_h__
+#define txStringUtils_h__
+
+#include "nsAString.h"
+#include "nsAtom.h"
+#include "nsUnicharUtils.h"
+#include "nsContentUtils.h"  // For ASCIIToLower().
+
+/**
+ * Check equality between a string and an atom containing ASCII.
+ */
+inline bool TX_StringEqualsAtom(const nsAString& aString, nsAtom* aAtom) {
+  return aAtom->Equals(aString);
+}
+
+inline already_AddRefed<nsAtom> TX_ToLowerCaseAtom(nsAtom* aAtom) {
+  nsAutoString str;
+  aAtom->ToString(str);
+  nsContentUtils::ASCIIToLower(str);
+  return NS_Atomize(str);
+}
+
+#endif  // txStringUtils_h__
diff --git a/dom/xslt/base/txURIUtils.cpp b/dom/xslt/base/txURIUtils.cpp
new file mode 100644
index 0000000000..bbb06221cf
--- /dev/null
+++ b/dom/xslt/base/txURIUtils.cpp
@@ -0,0 +1,87 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "txURIUtils.h"
+#include "nsNetUtil.h"
+#include "mozilla/dom/Document.h"
+#include "nsIPrincipal.h"
+#include "mozilla/LoadInfo.h"
+#include "mozilla/dom/nsCSPContext.h"
+
+using mozilla::dom::Document;
+using mozilla::net::LoadInfo;
+
+/**
+ * URIUtils
+ * A set of utilities for handling URIs
+ **/
+
+/**
+ * Resolves the given href argument, using the given documentBase
+ * if necessary.
+ * The new resolved href will be appended to the given dest String
+ **/
+void URIUtils::resolveHref(const nsAString& href, const nsAString& base,
+                           nsAString& dest) {
+  if (base.IsEmpty()) {
+    dest.Append(href);
+    return;
+  }
+  if (href.IsEmpty()) {
+    dest.Append(base);
+    return;
+  }
+  nsCOMPtr<nsIURI> pURL;
+  nsAutoString resultHref;
+  nsresult result = NS_NewURI(getter_AddRefs(pURL), base);
+  if (NS_SUCCEEDED(result)) {
+    NS_MakeAbsoluteURI(resultHref, href, pURL);
+    dest.Append(resultHref);
+  }
+}  //-- resolveHref
+
+// static
+void URIUtils::ResetWithSource(Document* aNewDoc, nsINode* aSourceNode) {
+  nsCOMPtr<Document> sourceDoc = aSourceNode->OwnerDoc();
+  nsIPrincipal* sourcePrincipal = sourceDoc->NodePrincipal();
+  nsIPrincipal* sourcePartitionedPrincipal = sourceDoc->PartitionedPrincipal();
+
+  // Copy the channel and loadgroup from the source document.
+  nsCOMPtr<nsILoadGroup> loadGroup = sourceDoc->GetDocumentLoadGroup();
+  nsCOMPtr<nsIChannel> channel = sourceDoc->GetChannel();
+  if (!channel) {
+    // Need to synthesize one
+    nsresult rv = NS_NewChannel(
+        getter_AddRefs(channel), sourceDoc->GetDocumentURI(), sourceDoc,
+        nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL, nsIContentPolicy::TYPE_OTHER,
+        nullptr,  // aPerformanceStorage
+        loadGroup,
+        nullptr,  // aCallbacks
+        nsIChannel::LOAD_BYPASS_SERVICE_WORKER);
+
+    if (NS_FAILED(rv)) {
+      return;
+    }
+  }
+
+  aNewDoc->Reset(channel, loadGroup);
+  aNewDoc->SetPrincipals(sourcePrincipal, sourcePartitionedPrincipal);
+  aNewDoc->SetBaseURI(sourceDoc->GetDocBaseURI());
+  aNewDoc->SetSandboxFlags(sourceDoc->GetSandboxFlags());
+  aNewDoc->SetReferrerInfo(sourceDoc->GetReferrerInfo());
+  aNewDoc->SetEmbedderPolicy(sourceDoc->GetEmbedderPolicy());
+
+  // Inherit the csp if there is one
+  nsCOMPtr<nsIContentSecurityPolicy> csp = sourceDoc->GetCsp();
+  if (csp) {
+    RefPtr<nsCSPContext> cspToInherit = new nsCSPContext();
+    cspToInherit->InitFromOther(static_cast<nsCSPContext*>(csp.get()));
+    aNewDoc->SetCsp(cspToInherit);
+  }
+  // Copy charset
+  aNewDoc->SetDocumentCharacterSetSource(
+      sourceDoc->GetDocumentCharacterSetSource());
+  aNewDoc->SetDocumentCharacterSet(sourceDoc->GetDocumentCharacterSet());
+}
diff --git a/dom/xslt/base/txURIUtils.h b/dom/xslt/base/txURIUtils.h
new file mode 100644
index 0000000000..96082b99f7
--- /dev/null
+++ b/dom/xslt/base/txURIUtils.h
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#ifndef TRANSFRMX_URIUTILS_H
+#define TRANSFRMX_URIUTILS_H
+
+#include "txCore.h"
+
+class nsINode;
+
+namespace mozilla::dom {
+class Document;
+}  // namespace mozilla::dom
+
+/**
+ * A utility class for URI handling
+ * Not yet finished, only handles file URI at this point
+ **/
+
+class URIUtils {
+ public:
+  /**
+   * Reset the given document with the document of the source node
+   */
+  static void ResetWithSource(mozilla::dom::Document* aNewDoc,
+                              nsINode* aSourceNode);
+
+  /**
+   * Resolves the given href argument, using the given documentBase
+   * if necessary.
+   * The new resolved href will be appended to the given dest String
+   **/
+  static void resolveHref(const nsAString& href, const nsAString& base,
+                          nsAString& dest);
+};  //-- URIUtils
+
+/* */
+#endif