Bug 389767 ��� Regression: Fixed-position items are missing on 2nd page of print-preview, fixed on behalf of HP, r+sr=bzbarsky

layout/base/nsCSSFrameConstructor.cpp

@@ -4649,8 +4649,6 @@ nsCSSFrameConstructor::ConstructPageFrame(nsIPresShell*   aPresShell,
 
   aPageFrame->SetInitialChildList(nsnull, aPageContentFrame);
 
-  // Fixed pos kids are taken care of directly in CreateContinuingFrame()
-
   return NS_OK;
 }
 
@@ -10605,75 +10603,58 @@ nsCSSFrameConstructor::CreateContinuingFrame(nsPresContext* aPresContext,
   if (aFrame->GetStateBits() & NS_FRAME_GENERATED_CONTENT) {
     newFrame->AddStateBits(NS_FRAME_GENERATED_CONTENT);
   }
-  
+
+  if (nextInFlow) {
+    nextInFlow->SetPrevInFlow(newFrame);
+    newFrame->SetNextInFlow(nextInFlow);
+  } else if (nextContinuation) {
+    nextContinuation->SetPrevContinuation(newFrame);
+    newFrame->SetNextContinuation(nextContinuation);
+  }
+  return NS_OK;
+}
+
+nsresult
+nsCSSFrameConstructor::ReplicateFixedFrames(nsPageContentFrame* aParentFrame)
+{
   // Now deal with fixed-pos things....  They should appear on all pages, and
   // the placeholders must be kids of a block, so we want to move over the
   // placeholders when processing the child of the pageContentFrame.
-  if (!aParentFrame) {
-    return NS_OK;
-  }
-
-  if (aParentFrame->GetType() != nsGkAtoms::pageContentFrame) {
-    if (nextInFlow) {
-      nextInFlow->SetPrevInFlow(newFrame);
-      newFrame->SetNextInFlow(nextInFlow);
-    } else if (nextContinuation) {
-      nextContinuation->SetPrevContinuation(newFrame);
-      newFrame->SetNextContinuation(nextContinuation);
-    }
-    return NS_OK;
-  }
-
-  // Our parent is a page content frame.  Look up its page frame and
-  // see whether it has a prev-in-flow.
-  nsIFrame* pageFrame = aParentFrame->GetParent();
-  if (!pageFrame) {
-    NS_ERROR("pageContentFrame does not have parent!");
-    newFrame->Destroy();
-    *aContinuingFrame = nsnull;
-    return NS_ERROR_UNEXPECTED;
-  }
-
-  nsIFrame* prevPage = pageFrame->GetPrevInFlow();
-  if (!prevPage) {
-    return NS_OK;
-  }
-
-  // OK.  now we need to do this fixed-pos game.
-  // Get prevPage's page content frame
-  nsIFrame* prevPageContentFrame = prevPage->GetFirstChild(nsnull);
 
+  nsIFrame* prevPageContentFrame = aParentFrame->GetPrevInFlow();
   if (!prevPageContentFrame) {
-    newFrame->Destroy();
+    return NS_OK;
-    *aContinuingFrame = nsnull;
+  }
+  nsIFrame* docRootFrame = aParentFrame->GetFirstChild(nsnull);
+  if (!docRootFrame) {
+    // document's root element's frame: don't need a page if there's no content
     return NS_ERROR_UNEXPECTED;
   }
-  
+
   nsFrameItems fixedPlaceholders;
   nsIFrame* firstFixed = prevPageContentFrame->GetFirstChild(nsGkAtoms::fixedList);
   if (!firstFixed) {
     return NS_OK;
   }
 
+  //XXXbz Should mInitialContainingBlock be docRootFrame? It probably doesn't matter.
   nsFrameConstructorState state(mPresShell, aParentFrame,
                                 mInitialContainingBlock,
                                 mInitialContainingBlock);
   
   // Iterate the fixed frames and replicate each
   for (nsIFrame* fixed = firstFixed; fixed; fixed = fixed->GetNextSibling()) {
-    rv = ConstructFrame(state, fixed->GetContent(),
+    nsresult rv = ConstructFrame(state, fixed->GetContent(),
-                        newFrame, fixedPlaceholders);
+                                 docRootFrame, fixedPlaceholders);
-    if (NS_FAILED(rv)) {
+    NS_ENSURE_SUCCESS(rv, rv);
-      newFrame->Destroy();
-      *aContinuingFrame = nsnull;
-      return rv;
-    }
   }
 
   // Add the placeholders to our primary child list.
   // XXXbz this is a little screwed up, since the fixed frames will have the
   // wrong parent block and hence auto-positioning will be broken.  Oh, well.
-  newFrame->SetInitialChildList(nsnull, fixedPlaceholders.childList);
+  NS_ASSERTION(!docRootFrame->GetFirstChild(nsnull),
+               "leaking frames; doc root continuation must be empty");
+  docRootFrame->SetInitialChildList(nsnull, fixedPlaceholders.childList);
   return NS_OK;
 }
 

layout/base/nsCSSFrameConstructor.h

@@ -51,6 +51,7 @@
 #include "nsDataHashtable.h"
 #include "nsHashKeys.h"
 #include "nsThreadUtils.h"
+#include "nsPageContentFrame.h"
 
 class nsIDocument;
 struct nsFrameItems;
@@ -185,6 +186,9 @@ public:
                                  nsIFrame**      aContinuingFrame,
                                  PRBool          aIsFluid = PR_TRUE);
 
+  // Copy over fixed frames from aParentFrame's prev-in-flow
+  nsresult ReplicateFixedFrames(nsPageContentFrame* aParentFrame);
+
   // Request to find the primary frame associated with a given content object.
   // This is typically called by the pres shell when there is no mapping in
   // the pres shell hash table

layout/generic/nsPageContentFrame.cpp

@@ -65,15 +65,24 @@ nsPageContentFrame::Reflow(nsPresContext*           aPresContext,
   DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
   aStatus = NS_FRAME_COMPLETE;  // initialize out parameter
 
+  // A PageContentFrame must always have one child: the doc root element's frame.
+  // We only need to get overflow frames if we don't already have that child;
+  // Also we need to avoid repeating the call to ReplicateFixedFrames.
   nsPageContentFrame* prevPageContentFrame = static_cast<nsPageContentFrame*>
-                                             (GetPrevInFlow());
+                                               (GetPrevInFlow());
-  if (prevPageContentFrame) {
+  if (mFrames.IsEmpty() && prevPageContentFrame) {
+    // Pull the doc root frame's continuation and copy fixed frames.
     nsIFrame* overflow = prevPageContentFrame->GetOverflowFrames(aPresContext, PR_TRUE);
-    nsHTMLContainerFrame::ReparentFrameViewList(aPresContext, overflow, prevPageContentFrame, this);
+    NS_ASSERTION(overflow && !overflow->GetNextSibling(),
+                 "must have doc root as pageContentFrame's only child");
+    nsHTMLContainerFrame::ReparentFrameView(aPresContext, overflow, prevPageContentFrame, this);
     // Prepend overflow to the page content frame. There may already be
     // children placeholders which don't get reflowed but must not be
     // lost until the page content frame is destroyed.
     mFrames.InsertFrames(this, nsnull, overflow);
+    nsresult rv = aPresContext->PresShell()->FrameConstructor()
+                    ->ReplicateFixedFrames(this);
+    NS_ENSURE_SUCCESS(rv, rv);
   }
 
   // Resize our frame allowing it only to be as big as we are