https://bugzilla.mozilla.org/show_bug.cgi?id=774423

static-clone2.diff

diff --git a/content/base/public/nsIDocument.h b/content/base/public/nsIDocument.h
--- a/content/base/public/nsIDocument.h
+++ b/content/base/public/nsIDocument.h
@@ -1424,17 +1424,17 @@ public:
    */
   bool IsStaticDocument() { return mIsStaticDocument; }
 
   /**
    * Clones the document and subdocuments and stylesheet etc.
    * @param aCloneContainer The container for the clone document.
    */
   virtual already_AddRefed<nsIDocument>
-  CreateStaticClone(nsISupports* aCloneContainer);
+  CreateStaticClone(nsISupports* aCloneContainer, bool aPreserveLoadedAsData = false);
 
   /**
    * If this document is a static clone, this returns the original
    * document.
    */
   nsIDocument* GetOriginalDocument()
   {
     MOZ_ASSERT(!mOriginalDocument || !mOriginalDocument->GetOriginalDocument());
@@ -1815,16 +1815,20 @@ protected:
   bool mAllowDNSPrefetch;
   
   // True when this document is a static clone of a normal document
   bool mIsStaticDocument;
 
   // True while this document is being cloned to a static document.
   bool mCreatingStaticClone;
 
+  // True while this document transfers the LoadedAsData attribute to the
+  // cloned document.
+  bool mPreserveLoadedAsData;
+
   // True iff the document is being unlinked or deleted.
   bool mInUnlinkOrDeletion;
 
   // True if document has ever had script handling object.
   bool mHasHadScriptHandlingObject;
 
   // True if we're an SVG document being used as an image.
   bool mIsBeingUsedAsImage;
diff --git a/content/base/src/nsDocument.cpp b/content/base/src/nsDocument.cpp
--- a/content/base/src/nsDocument.cpp
+++ b/content/base/src/nsDocument.cpp
@@ -7517,17 +7517,17 @@ nsDocument::CloneDocHelper(nsDocument* c
   // Set scripting object
   bool hasHadScriptObject = true;
   nsIScriptGlobalObject* scriptObject =
     GetScriptHandlingObject(hasHadScriptObject);
   NS_ENSURE_STATE(scriptObject || !hasHadScriptObject);
   clone->SetScriptHandlingObject(scriptObject);
 
   // Make the clone a data document
-  clone->SetLoadedAsData(true);
+  clone->SetLoadedAsData(mPreserveLoadedAsData ? mLoadedAsData : true);
 
   // Misc state
 
   // State from nsIDocument
   clone->mCharacterSet = mCharacterSet;
   clone->mCharacterSetSource = mCharacterSetSource;
   clone->mCompatMode = mCompatMode;
   clone->mBidiOptions = mBidiOptions;
@@ -7983,21 +7983,22 @@ nsIDocument::FlushPendingLinkUpdates()
     
   nsAutoScriptBlocker scriptBlocker;
   mLinksToUpdate.EnumerateEntries(EnumeratePendingLinkUpdates, nullptr);
   mLinksToUpdate.Clear();
   mHasLinksToUpdate = false;
 }
 
 already_AddRefed<nsIDocument>
-nsIDocument::CreateStaticClone(nsISupports* aCloneContainer)
+nsIDocument::CreateStaticClone(nsISupports* aCloneContainer, bool aPreserveLoadedAsData)
 {
   nsCOMPtr<nsIDOMDocument> domDoc = do_QueryInterface(this);
   NS_ENSURE_TRUE(domDoc, nullptr);
   mCreatingStaticClone = true;
+  mPreserveLoadedAsData = aPreserveLoadedAsData;
 
   // Make document use different container during cloning.
   nsCOMPtr<nsISupports> originalContainer = GetContainer();
   SetContainer(aCloneContainer);
   nsCOMPtr<nsIDOMNode> clonedNode;
   nsresult rv = domDoc->CloneNode(true, 1, getter_AddRefs(clonedNode));
   SetContainer(originalContainer);
 
diff --git a/docshell/base/nsIContentViewer.idl b/docshell/base/nsIContentViewer.idl
--- a/docshell/base/nsIContentViewer.idl
+++ b/docshell/base/nsIContentViewer.idl
@@ -22,17 +22,17 @@ class nsDOMNavigationTiming;
 [ptr] native nsIWidgetPtr(nsIWidget);
 [ptr] native nsIDocumentPtr(nsIDocument);
 [ref] native nsIntRectRef(nsIntRect);
 [ptr] native nsIPresShellPtr(nsIPresShell);
 [ptr] native nsPresContextPtr(nsPresContext);
 [ptr] native nsIViewPtr(nsIView);
 [ptr] native nsDOMNavigationTimingPtr(nsDOMNavigationTiming);
 
-[scriptable, builtinclass, uuid(26b2380b-4a1a-46cd-b7d8-7600e41c1688)]
+[scriptable, builtinclass, uuid(2f437a72-386b-4a3f-86f2-b7cce6d6d75d)]
 interface nsIContentViewer : nsISupports
 {
 
   [noscript] void init(in nsIWidgetPtr aParentWidget,
                        [const] in nsIntRectRef aBounds);
 
   attribute nsISupports container;
 
@@ -133,17 +133,17 @@ interface nsIContentViewer : nsISupports
    * the saved presentation state.
    */
   void clearHistoryEntry();
 
   /*
    * Change the layout to view the document with page layout (like print preview), but
    * dynamic and editable (like Galley layout).
   */
-  void setPageMode(in boolean aPageMode, in nsIPrintSettings aPrintSettings);
+  void setPageMode(in boolean aPageMode, in nsIPrintSettings aPrintSettings, in boolean aStaticClone);
 
   /**
    * Get the history entry that this viewer will save itself into when
    * destroyed.  Can return null
    */
   readonly attribute nsISHEntry historyEntry;
 
   /*
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -1789,20 +1789,23 @@ nsGlobalWindow::SetNewDocument(nsIDocume
   }
 
   NS_ASSERTION(!GetCurrentInnerWindow() ||
                GetCurrentInnerWindow()->GetExtantDocument() == mDocument,
                "Uh, mDocument doesn't match the current inner window "
                "document!");
 
   bool wouldReuseInnerWindow = WouldReuseInnerWindow(aDocument);
+  bool equal;
   if (aForceReuseInnerWindow &&
       !wouldReuseInnerWindow &&
       mDoc &&
-      mDoc->NodePrincipal() != aDocument->NodePrincipal()) {
+      (!NS_SUCCEEDED(mDoc->NodePrincipal()->Equals(aDocument->NodePrincipal(),
+                                                   &equal)) ||
+       !equal)) {
     NS_ERROR("Attempted forced inner window reuse while changing principal");
     return NS_ERROR_UNEXPECTED;
   }
 
   nsCOMPtr<nsIDocument> oldDoc(do_QueryInterface(mDocument));
 
   nsIScriptContext *scx = GetContextInternal();
   NS_ENSURE_TRUE(scx, NS_ERROR_NOT_INITIALIZED);
diff --git a/layout/base/nsDocumentViewer.cpp b/layout/base/nsDocumentViewer.cpp
--- a/layout/base/nsDocumentViewer.cpp
+++ b/layout/base/nsDocumentViewer.cpp
@@ -4257,17 +4257,18 @@ DocumentViewerImpl::OnDonePrinting()
         mDocument = nullptr;
       }
       mClosingWhilePrinting = false;
     }
   }
 #endif // NS_PRINTING && NS_PRINT_PREVIEW
 }
 
-NS_IMETHODIMP DocumentViewerImpl::SetPageMode(bool aPageMode, nsIPrintSettings* aPrintSettings)
+NS_IMETHODIMP DocumentViewerImpl::SetPageMode(bool aPageMode, nsIPrintSettings* aPrintSettings,
+                                              bool aStaticClone)
 {
   // XXX Page mode is only partially working; it's currently used for
   // reftests that require a paginated context
   mIsPageMode = aPageMode;
 
   if (mPresShell) {
     DestroyPresShell();
   }
@@ -4275,16 +4276,26 @@ NS_IMETHODIMP DocumentViewerImpl::SetPag
   if (mPresContext) {
     DestroyPresContext();
   }
 
   mViewManager  = nullptr;
   mWindow       = nullptr;
 
   NS_ENSURE_STATE(mDocument);
+  if (aStaticClone) {
+    nsPIDOMWindow *window = mDocument->GetWindow();
+    nsIDocShell *docShell = window->GetDocShell();
+    NS_ENSURE_TRUE(docShell, NS_ERROR_UNEXPECTED);
+
+    nsCOMPtr<nsIDocument> clonedDoc = mDocument->CreateStaticClone(docShell, true);
+    mDocument->OnPageHide(false, nsnull);
+    mDocument->Destroy();
+    SetDocumentInternal(clonedDoc, true);
+  }
   if (aPageMode)
   {    
     mPresContext = CreatePresContext(mDocument,
         nsPresContext::eContext_PageLayout, FindContainerView());
     NS_ENSURE_TRUE(mPresContext, NS_ERROR_OUT_OF_MEMORY);
     mPresContext->SetPaginatedScrolling(true);
     mPresContext->SetPrintSettings(aPrintSettings);
     nsresult rv = mPresContext->Init(mDeviceContext);
diff --git a/layout/tools/reftest/reftest-content.js b/layout/tools/reftest/reftest-content.js
--- a/layout/tools/reftest/reftest-content.js
+++ b/layout/tools/reftest/reftest-content.js
@@ -198,17 +198,17 @@ function setupPrintMode() {
    ps.unwriteableMarginRight = 0;
 
    ps.headerStrLeft = "";
    ps.headerStrCenter = "";
    ps.headerStrRight = "";
    ps.footerStrLeft = "";
    ps.footerStrCenter = "";
    ps.footerStrRight = "";
-   docShell.contentViewer.setPageMode(true, ps);
+   docShell.contentViewer.setPageMode(true, ps, true);
 }
 
 function setupDisplayport(contentRootElement) {
     if (!contentRootElement) {
         return;
     }
 
     function attrOrDefault(attr, def) {
@@ -312,17 +312,20 @@ function WaitForTestEnd(contentRootEleme
         if (anyPendingPaintsGeneratedInDescendants &&
             !windowUtils().isMozAfterPaintPending) {
             LogWarning("Internal error: descendant frame generated a MozAfterPaint event, but the root document doesn't have one!");
         }
     }
 
     function AfterPaintListener(event) {
         LogInfo("AfterPaintListener in " + event.target.document.location.href);
-        if (event.target.document != currentDoc) {
+        // Use the docShell doc instead of currentDoc because in print mode a
+        // clone of the document is made which means currentDoc no longer
+        // matches event.target.document.
+        if (event.target.document != docShell.contentViewer.DOMDocument) {
             // ignore paint events for subframes or old documents in the window.
             // Invalidation in subframes will cause invalidation in the toplevel document anyway.
             return;
         }
 
         SendUpdateCanvasForEvent(event);
         // These events are fired immediately after a paint. Don't
         // confuse ourselves by firing synchronously if we triggered the