Add m-esr52 at 52.6.0

1 files changed, 944 insertions, 0 deletions

diff --git a/docshell/shistory/nsSHEntry.cpp b/docshell/shistory/nsSHEntry.cpp
new file mode 100644
index 000000000..9d972136f
--- /dev/null
+++ b/docshell/shistory/nsSHEntry.cpp
@@ -0,0 +1,944 @@
+/* -*- 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/. */
+
+#include "nsSHEntry.h"
+#include "nsIDocShellLoadInfo.h"
+#include "nsIDocShellTreeItem.h"
+#include "nsDocShellEditorData.h"
+#include "nsSHEntryShared.h"
+#include "nsILayoutHistoryState.h"
+#include "nsIContentViewer.h"
+#include "nsIStructuredCloneContainer.h"
+#include "nsIInputStream.h"
+#include "nsIURI.h"
+#include "mozilla/net/ReferrerPolicy.h"
+#include <algorithm>
+
+namespace dom = mozilla::dom;
+
+static uint32_t gEntryID = 0;
+
+nsSHEntry::nsSHEntry()
+  : mShared(new nsSHEntryShared())
+  , mLoadReplace(false)
+  , mReferrerPolicy(mozilla::net::RP_Default)
+  , mLoadType(0)
+  , mID(gEntryID++)
+  , mScrollPositionX(0)
+  , mScrollPositionY(0)
+  , mParent(nullptr)
+  , mURIWasModified(false)
+  , mIsSrcdocEntry(false)
+  , mScrollRestorationIsManual(false)
+{
+}
+
+nsSHEntry::nsSHEntry(const nsSHEntry& aOther)
+  : mShared(aOther.mShared)
+  , mURI(aOther.mURI)
+  , mOriginalURI(aOther.mOriginalURI)
+  , mLoadReplace(aOther.mLoadReplace)
+  , mReferrerURI(aOther.mReferrerURI)
+  , mReferrerPolicy(aOther.mReferrerPolicy)
+  , mTitle(aOther.mTitle)
+  , mPostData(aOther.mPostData)
+  , mLoadType(0)         // XXX why not copy?
+  , mID(aOther.mID)
+  , mScrollPositionX(0)  // XXX why not copy?
+  , mScrollPositionY(0)  // XXX why not copy?
+  , mParent(aOther.mParent)
+  , mURIWasModified(aOther.mURIWasModified)
+  , mStateData(aOther.mStateData)
+  , mIsSrcdocEntry(aOther.mIsSrcdocEntry)
+  , mScrollRestorationIsManual(false)
+  , mSrcdocData(aOther.mSrcdocData)
+  , mBaseURI(aOther.mBaseURI)
+{
+}
+
+static bool
+ClearParentPtr(nsISHEntry* aEntry, void* /* aData */)
+{
+  if (aEntry) {
+    aEntry->SetParent(nullptr);
+  }
+  return true;
+}
+
+nsSHEntry::~nsSHEntry()
+{
+  // Null out the mParent pointers on all our kids.
+  mChildren.EnumerateForwards(ClearParentPtr, nullptr);
+}
+
+NS_IMPL_ISUPPORTS(nsSHEntry, nsISHContainer, nsISHEntry, nsISHEntryInternal)
+
+NS_IMETHODIMP
+nsSHEntry::SetScrollPosition(int32_t aX, int32_t aY)
+{
+  mScrollPositionX = aX;
+  mScrollPositionY = aY;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetScrollPosition(int32_t* aX, int32_t* aY)
+{
+  *aX = mScrollPositionX;
+  *aY = mScrollPositionY;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetURIWasModified(bool* aOut)
+{
+  *aOut = mURIWasModified;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetURIWasModified(bool aIn)
+{
+  mURIWasModified = aIn;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetURI(nsIURI** aURI)
+{
+  *aURI = mURI;
+  NS_IF_ADDREF(*aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetURI(nsIURI* aURI)
+{
+  mURI = aURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetOriginalURI(nsIURI** aOriginalURI)
+{
+  *aOriginalURI = mOriginalURI;
+  NS_IF_ADDREF(*aOriginalURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetOriginalURI(nsIURI* aOriginalURI)
+{
+  mOriginalURI = aOriginalURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetLoadReplace(bool* aLoadReplace)
+{
+  *aLoadReplace = mLoadReplace;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetLoadReplace(bool aLoadReplace)
+{
+  mLoadReplace = aLoadReplace;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetReferrerURI(nsIURI** aReferrerURI)
+{
+  *aReferrerURI = mReferrerURI;
+  NS_IF_ADDREF(*aReferrerURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetReferrerURI(nsIURI* aReferrerURI)
+{
+  mReferrerURI = aReferrerURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetReferrerPolicy(uint32_t* aReferrerPolicy)
+{
+  *aReferrerPolicy = mReferrerPolicy;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetReferrerPolicy(uint32_t aReferrerPolicy)
+{
+  mReferrerPolicy = aReferrerPolicy;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetContentViewer(nsIContentViewer* aViewer)
+{
+  return mShared->SetContentViewer(aViewer);
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetContentViewer(nsIContentViewer** aResult)
+{
+  *aResult = mShared->mContentViewer;
+  NS_IF_ADDREF(*aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetAnyContentViewer(nsISHEntry** aOwnerEntry,
+                               nsIContentViewer** aResult)
+{
+  // Find a content viewer in the root node or any of its children,
+  // assuming that there is only one content viewer total in any one
+  // nsSHEntry tree
+  GetContentViewer(aResult);
+  if (*aResult) {
+#ifdef DEBUG_PAGE_CACHE
+    printf("Found content viewer\n");
+#endif
+    *aOwnerEntry = this;
+    NS_ADDREF(*aOwnerEntry);
+    return NS_OK;
+  }
+  // The root SHEntry doesn't have a ContentViewer, so check child nodes
+  for (int32_t i = 0; i < mChildren.Count(); i++) {
+    nsISHEntry* child = mChildren[i];
+    if (child) {
+#ifdef DEBUG_PAGE_CACHE
+      printf("Evaluating SHEntry child %d\n", i);
+#endif
+      child->GetAnyContentViewer(aOwnerEntry, aResult);
+      if (*aResult) {
+        return NS_OK;
+      }
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetSticky(bool aSticky)
+{
+  mShared->mSticky = aSticky;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetSticky(bool* aSticky)
+{
+  *aSticky = mShared->mSticky;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetTitle(char16_t** aTitle)
+{
+  // Check for empty title...
+  if (mTitle.IsEmpty() && mURI) {
+    // Default title is the URL.
+    nsAutoCString spec;
+    if (NS_SUCCEEDED(mURI->GetSpec(spec))) {
+      AppendUTF8toUTF16(spec, mTitle);
+    }
+  }
+
+  *aTitle = ToNewUnicode(mTitle);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetTitle(const nsAString& aTitle)
+{
+  mTitle = aTitle;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetPostData(nsIInputStream** aResult)
+{
+  *aResult = mPostData;
+  NS_IF_ADDREF(*aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetPostData(nsIInputStream* aPostData)
+{
+  mPostData = aPostData;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetLayoutHistoryState(nsILayoutHistoryState** aResult)
+{
+  *aResult = mShared->mLayoutHistoryState;
+  NS_IF_ADDREF(*aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetLayoutHistoryState(nsILayoutHistoryState* aState)
+{
+  mShared->mLayoutHistoryState = aState;
+  if (mShared->mLayoutHistoryState) {
+    mShared->mLayoutHistoryState->SetScrollPositionOnly(
+      !mShared->mSaveLayoutState);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetLoadType(uint32_t* aResult)
+{
+  *aResult = mLoadType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetLoadType(uint32_t aLoadType)
+{
+  mLoadType = aLoadType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetID(uint32_t* aResult)
+{
+  *aResult = mID;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetID(uint32_t aID)
+{
+  mID = aID;
+  return NS_OK;
+}
+
+nsSHEntryShared*
+nsSHEntry::GetSharedState()
+{
+  return mShared;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetIsSubFrame(bool* aFlag)
+{
+  *aFlag = mShared->mIsFrameNavigation;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetIsSubFrame(bool aFlag)
+{
+  mShared->mIsFrameNavigation = aFlag;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetCacheKey(nsISupports** aResult)
+{
+  *aResult = mShared->mCacheKey;
+  NS_IF_ADDREF(*aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetCacheKey(nsISupports* aCacheKey)
+{
+  mShared->mCacheKey = aCacheKey;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetSaveLayoutStateFlag(bool* aFlag)
+{
+  *aFlag = mShared->mSaveLayoutState;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetSaveLayoutStateFlag(bool aFlag)
+{
+  mShared->mSaveLayoutState = aFlag;
+  if (mShared->mLayoutHistoryState) {
+    mShared->mLayoutHistoryState->SetScrollPositionOnly(!aFlag);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetExpirationStatus(bool* aFlag)
+{
+  *aFlag = mShared->mExpired;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetExpirationStatus(bool aFlag)
+{
+  mShared->mExpired = aFlag;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetContentType(nsACString& aContentType)
+{
+  aContentType = mShared->mContentType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetContentType(const nsACString& aContentType)
+{
+  mShared->mContentType = aContentType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::Create(nsIURI* aURI, const nsAString& aTitle,
+                  nsIInputStream* aInputStream,
+                  nsILayoutHistoryState* aLayoutHistoryState,
+                  nsISupports* aCacheKey, const nsACString& aContentType,
+                  nsIPrincipal* aTriggeringPrincipal,
+                  nsIPrincipal* aPrincipalToInherit,
+                  uint64_t aDocShellID,
+                  bool aDynamicCreation)
+{
+  mURI = aURI;
+  mTitle = aTitle;
+  mPostData = aInputStream;
+
+  // Set the LoadType by default to loadHistory during creation
+  mLoadType = (uint32_t)nsIDocShellLoadInfo::loadHistory;
+
+  mShared->mCacheKey = aCacheKey;
+  mShared->mContentType = aContentType;
+  mShared->mTriggeringPrincipal = aTriggeringPrincipal;
+  mShared->mPrincipalToInherit = aPrincipalToInherit;
+  mShared->mDocShellID = aDocShellID;
+  mShared->mDynamicallyCreated = aDynamicCreation;
+
+  // By default all entries are set false for subframe flag.
+  // nsDocShell::CloneAndReplace() which creates entries for
+  // all subframe navigations, sets the flag to true.
+  mShared->mIsFrameNavigation = false;
+
+  // By default we save LayoutHistoryState
+  mShared->mSaveLayoutState = true;
+  mShared->mLayoutHistoryState = aLayoutHistoryState;
+
+  // By default the page is not expired
+  mShared->mExpired = false;
+
+  mIsSrcdocEntry = false;
+  mSrcdocData = NullString();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::Clone(nsISHEntry** aResult)
+{
+  *aResult = new nsSHEntry(*this);
+  NS_ADDREF(*aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetParent(nsISHEntry** aResult)
+{
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = mParent;
+  NS_IF_ADDREF(*aResult);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetParent(nsISHEntry* aParent)
+{
+  /* parent not Addrefed on purpose to avoid cyclic reference
+   * Null parent is OK
+   *
+   * XXX this method should not be scriptable if this is the case!!
+   */
+  mParent = aParent;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetWindowState(nsISupports* aState)
+{
+  mShared->mWindowState = aState;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetWindowState(nsISupports** aState)
+{
+  NS_IF_ADDREF(*aState = mShared->mWindowState);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetViewerBounds(const nsIntRect& aBounds)
+{
+  mShared->mViewerBounds = aBounds;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetViewerBounds(nsIntRect& aBounds)
+{
+  aBounds = mShared->mViewerBounds;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetTriggeringPrincipal(nsIPrincipal** aTriggeringPrincipal)
+{
+  NS_IF_ADDREF(*aTriggeringPrincipal = mShared->mTriggeringPrincipal);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetTriggeringPrincipal(nsIPrincipal* aTriggeringPrincipal)
+{
+  mShared->mTriggeringPrincipal = aTriggeringPrincipal;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetPrincipalToInherit(nsIPrincipal** aPrincipalToInherit)
+{
+  NS_IF_ADDREF(*aPrincipalToInherit = mShared->mPrincipalToInherit);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetPrincipalToInherit(nsIPrincipal* aPrincipalToInherit)
+{
+  mShared->mPrincipalToInherit = aPrincipalToInherit;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetBFCacheEntry(nsIBFCacheEntry** aEntry)
+{
+  NS_ENSURE_ARG_POINTER(aEntry);
+  NS_IF_ADDREF(*aEntry = mShared);
+  return NS_OK;
+}
+
+bool
+nsSHEntry::HasBFCacheEntry(nsIBFCacheEntry* aEntry)
+{
+  return static_cast<nsIBFCacheEntry*>(mShared) == aEntry;
+}
+
+NS_IMETHODIMP
+nsSHEntry::AdoptBFCacheEntry(nsISHEntry* aEntry)
+{
+  nsCOMPtr<nsISHEntryInternal> shEntry = do_QueryInterface(aEntry);
+  NS_ENSURE_STATE(shEntry);
+
+  nsSHEntryShared* shared = shEntry->GetSharedState();
+  NS_ENSURE_STATE(shared);
+
+  mShared = shared;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SharesDocumentWith(nsISHEntry* aEntry, bool* aOut)
+{
+  NS_ENSURE_ARG_POINTER(aOut);
+
+  nsCOMPtr<nsISHEntryInternal> internal = do_QueryInterface(aEntry);
+  NS_ENSURE_STATE(internal);
+
+  *aOut = mShared == internal->GetSharedState();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::AbandonBFCacheEntry()
+{
+  mShared = nsSHEntryShared::Duplicate(mShared);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetIsSrcdocEntry(bool* aIsSrcdocEntry)
+{
+  *aIsSrcdocEntry = mIsSrcdocEntry;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetSrcdocData(nsAString& aSrcdocData)
+{
+  aSrcdocData = mSrcdocData;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetSrcdocData(const nsAString& aSrcdocData)
+{
+  mSrcdocData = aSrcdocData;
+  mIsSrcdocEntry = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetBaseURI(nsIURI** aBaseURI)
+{
+  *aBaseURI = mBaseURI;
+  NS_IF_ADDREF(*aBaseURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetBaseURI(nsIURI* aBaseURI)
+{
+  mBaseURI = aBaseURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetScrollRestorationIsManual(bool* aIsManual)
+{
+  *aIsManual = mScrollRestorationIsManual;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetScrollRestorationIsManual(bool aIsManual)
+{
+  mScrollRestorationIsManual = aIsManual;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetChildCount(int32_t* aCount)
+{
+  *aCount = mChildren.Count();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::AddChild(nsISHEntry* aChild, int32_t aOffset)
+{
+  if (aChild) {
+    NS_ENSURE_SUCCESS(aChild->SetParent(this), NS_ERROR_FAILURE);
+  }
+
+  if (aOffset < 0) {
+    mChildren.AppendObject(aChild);
+    return NS_OK;
+  }
+
+  //
+  // Bug 52670: Ensure children are added in order.
+  //
+  //  Later frames in the child list may load faster and get appended
+  //  before earlier frames, causing session history to be scrambled.
+  //  By growing the list here, they are added to the right position.
+  //
+  //  Assert that aOffset will not be so high as to grow us a lot.
+  //
+  NS_ASSERTION(aOffset < (mChildren.Count() + 1023), "Large frames array!\n");
+
+  bool newChildIsDyn = false;
+  if (aChild) {
+    aChild->IsDynamicallyAdded(&newChildIsDyn);
+  }
+
+  // If the new child is dynamically added, try to add it to aOffset, but if
+  // there are non-dynamically added children, the child must be after those.
+  if (newChildIsDyn) {
+    int32_t lastNonDyn = aOffset - 1;
+    for (int32_t i = aOffset; i < mChildren.Count(); ++i) {
+      nsISHEntry* entry = mChildren[i];
+      if (entry) {
+        bool dyn = false;
+        entry->IsDynamicallyAdded(&dyn);
+        if (dyn) {
+          break;
+        } else {
+          lastNonDyn = i;
+        }
+      }
+    }
+    // InsertObjectAt allows only appending one object.
+    // If aOffset is larger than Count(), we must first manually
+    // set the capacity.
+    if (aOffset > mChildren.Count()) {
+      mChildren.SetCount(aOffset);
+    }
+    if (!mChildren.InsertObjectAt(aChild, lastNonDyn + 1)) {
+      NS_WARNING("Adding a child failed!");
+      aChild->SetParent(nullptr);
+      return NS_ERROR_FAILURE;
+    }
+  } else {
+    // If the new child isn't dynamically added, it should be set to aOffset.
+    // If there are dynamically added children before that, those must be
+    // moved to be after aOffset.
+    if (mChildren.Count() > 0) {
+      int32_t start = std::min(mChildren.Count() - 1, aOffset);
+      int32_t dynEntryIndex = -1;
+      nsISHEntry* dynEntry = nullptr;
+      for (int32_t i = start; i >= 0; --i) {
+        nsISHEntry* entry = mChildren[i];
+        if (entry) {
+          bool dyn = false;
+          entry->IsDynamicallyAdded(&dyn);
+          if (dyn) {
+            dynEntryIndex = i;
+            dynEntry = entry;
+          } else {
+            break;
+          }
+        }
+      }
+
+      if (dynEntry) {
+        nsCOMArray<nsISHEntry> tmp;
+        tmp.SetCount(aOffset - dynEntryIndex + 1);
+        mChildren.InsertObjectsAt(tmp, dynEntryIndex);
+        NS_ASSERTION(mChildren[aOffset + 1] == dynEntry, "Whaat?");
+      }
+    }
+
+    // Make sure there isn't anything at aOffset.
+    if (aOffset < mChildren.Count()) {
+      nsISHEntry* oldChild = mChildren[aOffset];
+      if (oldChild && oldChild != aChild) {
+        NS_ERROR("Adding a child where we already have a child? This may misbehave");
+        oldChild->SetParent(nullptr);
+      }
+    }
+
+    mChildren.ReplaceObjectAt(aChild, aOffset);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::RemoveChild(nsISHEntry* aChild)
+{
+  NS_ENSURE_TRUE(aChild, NS_ERROR_FAILURE);
+  bool childRemoved = false;
+  bool dynamic = false;
+  aChild->IsDynamicallyAdded(&dynamic);
+  if (dynamic) {
+    childRemoved = mChildren.RemoveObject(aChild);
+  } else {
+    int32_t index = mChildren.IndexOfObject(aChild);
+    if (index >= 0) {
+      mChildren.ReplaceObjectAt(nullptr, index);
+      childRemoved = true;
+    }
+  }
+  if (childRemoved) {
+    aChild->SetParent(nullptr);
+
+    // reduce the child count, i.e. remove empty children at the end
+    for (int32_t i = mChildren.Count() - 1; i >= 0 && !mChildren[i]; --i) {
+      if (!mChildren.RemoveObjectAt(i)) {
+        break;
+      }
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetChildAt(int32_t aIndex, nsISHEntry** aResult)
+{
+  if (aIndex >= 0 && aIndex < mChildren.Count()) {
+    *aResult = mChildren[aIndex];
+    // yes, mChildren can have holes in it.  AddChild's offset parameter makes
+    // that possible.
+    NS_IF_ADDREF(*aResult);
+  } else {
+    *aResult = nullptr;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::ReplaceChild(nsISHEntry* aNewEntry)
+{
+  NS_ENSURE_STATE(aNewEntry);
+
+  uint64_t docshellID;
+  aNewEntry->GetDocshellID(&docshellID);
+
+  uint64_t otherID;
+  for (int32_t i = 0; i < mChildren.Count(); ++i) {
+    if (mChildren[i] && NS_SUCCEEDED(mChildren[i]->GetDocshellID(&otherID)) &&
+        docshellID == otherID) {
+      mChildren[i]->SetParent(nullptr);
+      mChildren.ReplaceObjectAt(aNewEntry, i);
+      return aNewEntry->SetParent(this);
+    }
+  }
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsSHEntry::AddChildShell(nsIDocShellTreeItem* aShell)
+{
+  NS_ASSERTION(aShell, "Null child shell added to history entry");
+  mShared->mChildShells.AppendObject(aShell);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::ChildShellAt(int32_t aIndex, nsIDocShellTreeItem** aShell)
+{
+  NS_IF_ADDREF(*aShell = mShared->mChildShells.SafeObjectAt(aIndex));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::ClearChildShells()
+{
+  mShared->mChildShells.Clear();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetRefreshURIList(nsIMutableArray** aList)
+{
+  NS_IF_ADDREF(*aList = mShared->mRefreshURIList);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetRefreshURIList(nsIMutableArray* aList)
+{
+  mShared->mRefreshURIList = aList;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SyncPresentationState()
+{
+  return mShared->SyncPresentationState();
+}
+
+void
+nsSHEntry::RemoveFromBFCacheSync()
+{
+  mShared->RemoveFromBFCacheSync();
+}
+
+void
+nsSHEntry::RemoveFromBFCacheAsync()
+{
+  mShared->RemoveFromBFCacheAsync();
+}
+
+nsDocShellEditorData*
+nsSHEntry::ForgetEditorData()
+{
+  // XXX jlebar Check how this is used.
+  return mShared->mEditorData.forget();
+}
+
+void
+nsSHEntry::SetEditorData(nsDocShellEditorData* aData)
+{
+  NS_ASSERTION(!(aData && mShared->mEditorData),
+               "We're going to overwrite an owning ref!");
+  if (mShared->mEditorData != aData) {
+    mShared->mEditorData = aData;
+  }
+}
+
+bool
+nsSHEntry::HasDetachedEditor()
+{
+  return mShared->mEditorData != nullptr;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetStateData(nsIStructuredCloneContainer** aContainer)
+{
+  NS_ENSURE_ARG_POINTER(aContainer);
+  NS_IF_ADDREF(*aContainer = mStateData);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetStateData(nsIStructuredCloneContainer* aContainer)
+{
+  mStateData = aContainer;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::IsDynamicallyAdded(bool* aAdded)
+{
+  *aAdded = mShared->mDynamicallyCreated;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::HasDynamicallyAddedChild(bool* aAdded)
+{
+  *aAdded = false;
+  for (int32_t i = 0; i < mChildren.Count(); ++i) {
+    nsISHEntry* entry = mChildren[i];
+    if (entry) {
+      entry->IsDynamicallyAdded(aAdded);
+      if (*aAdded) {
+        break;
+      }
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetDocshellID(uint64_t* aID)
+{
+  *aID = mShared->mDocShellID;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetDocshellID(uint64_t aID)
+{
+  mShared->mDocShellID = aID;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::GetLastTouched(uint32_t* aLastTouched)
+{
+  *aLastTouched = mShared->mLastTouched;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsSHEntry::SetLastTouched(uint32_t aLastTouched)
+{
+  mShared->mLastTouched = aLastTouched;
+  return NS_OK;
+}