Bug 371536: Stop creating views for positioned elements. r+sr=roc.

layout/base/nsCSSFrameConstructor.cpp

@@ -9609,12 +9609,17 @@ DoApplyRenderingChangeToTree(nsIFrame* aFrame,
     UpdateViewsForTree(aFrame, aViewManager, aFrameManager, invalidRect,
                        aChange);
 
+    // if frame has view, will already be invalidated
     if (!aFrame->HasView()
         && (aChange & nsChangeHint_RepaintFrame)) {
-      // if frame has view, will already be invalidated
-      invalidRect -= aFrame->GetPosition();
-
-      aFrame->Invalidate(invalidRect, PR_FALSE);
+      if (aFrame->GetParent()) {
+        // Tell the parent to invalidate instead of the frame itself in case
+        // the child is clipping invalidates
+        aFrame->GetParent()->Invalidate(invalidRect);
+      } else {
+        invalidRect -= aFrame->GetPosition();
+        aFrame->Invalidate(invalidRect, PR_FALSE);
+      }
     }
   }
 }

layout/base/nsFrameManager.cpp

@@ -703,7 +703,9 @@ nsFrameManager::RemoveFrame(nsIFrame*       aParentFrame,
   // a gap where the old frame was, we invalidate it here.  (This is
   // reasonably likely to happen when removing a last child in a way
   // that doesn't change the size of the parent.)
-  aOldFrame->Invalidate(nsRect(nsPoint(0, 0), aOldFrame->GetSize()));
+  // This has to sure to invalidate the entire overflow rect; this
+  // is important in the presence of absolute positioning
+  aOldFrame->Invalidate(aOldFrame->GetOverflowRect());
 
   return aParentFrame->RemoveFrame(aListName, aOldFrame);
 }

layout/generic/nsAbsoluteContainingBlock.cpp

@@ -339,6 +339,12 @@ nsAbsoluteContainingBlock::ReflowAbsoluteFrame(nsIFrame*                aDelegat
   AutoNoisyIndenter indent(nsBlockFrame::gNoisy);
 #endif // DEBUG
 
+  // Store position and overflow rect so taht we can invalidate the correct
+  // area if the position changes
+  nsRect oldOverflowRect(aKidFrame->GetOverflowRect() +
+                         aKidFrame->GetPosition());
+  nsRect oldRect = aKidFrame->GetRect();
+
   nsresult  rv;
   // Get the border values
   const nsMargin& border = aReflowState.mStyleBorder->GetBorder();
@@ -373,12 +379,6 @@ nsAbsoluteContainingBlock::ReflowAbsoluteFrame(nsIFrame*                aDelegat
                                     kidReflowState.mComputedOffsets.top +
                                     kidReflowState.mComputedMargin.top));
 
-  // Position its view, but don't bother it doing it now if we haven't
-  // yet determined the left offset
-  if (NS_AUTOOFFSET != kidReflowState.mComputedOffsets.left) {
-    nsContainerFrame::PositionFrameView(aKidFrame);
-  }
-
   // Do the reflow
   rv = aKidFrame->Reflow(aPresContext, kidDesiredSize, kidReflowState, aStatus);
 
@@ -416,7 +416,6 @@ nsAbsoluteContainingBlock::ReflowAbsoluteFrame(nsIFrame*                aDelegat
   nsRect  rect(border.left + kidReflowState.mComputedOffsets.left + kidReflowState.mComputedMargin.left,
                border.top + kidReflowState.mComputedOffsets.top + kidReflowState.mComputedMargin.top,
                kidDesiredSize.width, kidDesiredSize.height);
-  nsRect oldRect = aKidFrame->GetRect();
   aKidFrame->SetRect(rect);
 
   // Size and position the view and set its opacity, visibility, content
@@ -424,15 +423,18 @@ nsAbsoluteContainingBlock::ReflowAbsoluteFrame(nsIFrame*                aDelegat
   nsContainerFrame::SyncFrameViewAfterReflow(aPresContext, aKidFrame,
                                              aKidFrame->GetView(),
                                              &kidDesiredSize.mOverflowArea);
-  // if the frame moved, then the view would have invalidated everything so
-  // we don't need to do any invalidation here.
-  if (oldRect.TopLeft() == rect.TopLeft() &&
-      !(aDelegatingFrame->GetStateBits() & NS_FRAME_FIRST_REFLOW) &&
-      oldRect.Size() != rect.Size()) {
-    // Invalidate the area where the frame changed size. We can't
-    // rely on the view to do this ... the view size might not change even
-    // though the frame size changed (and besides, views will go away).
-    // Invalidate the vertical strip
+
+  if (oldRect.TopLeft() != rect.TopLeft() || 
+      (aDelegatingFrame->GetStateBits() & NS_FRAME_FIRST_REFLOW)) {
+    // The frame moved; we have to invalidate the whole frame
+    // because the children may have moved after they were reflowed
+    // XXX This could be optimized in some cases, like repositioning and
+    // clipping
+    aKidFrame->GetParent()->Invalidate(oldOverflowRect);
+    aKidFrame->GetParent()->Invalidate(kidDesiredSize.mOverflowArea +
+                                       rect.TopLeft());
+  } else if (oldRect.Size() != rect.Size()) {
+    // Invalidate the area where the frame changed size.
     nscoord innerWidth = PR_MIN(oldRect.width, rect.width);
     nscoord innerHeight = PR_MIN(oldRect.height, rect.height);
     nscoord outerWidth = PR_MAX(oldRect.width, rect.width);

layout/generic/nsContainerFrame.cpp

@@ -630,15 +630,7 @@ nsContainerFrame::SyncFrameViewProperties(nsPresContext*  aPresContext,
 PRBool
 nsContainerFrame::FrameNeedsView(nsIFrame* aFrame)
 {
-  if (aFrame->NeedsView()) {
-    return PR_TRUE;
-  }
-    
-  if (aFrame->GetStyleContext()->GetStyleDisplay()->IsPositioned()) {
-    return PR_TRUE;
-  }
-
-  return PR_FALSE;
+  return aFrame->NeedsView();
 }
 
 static nscoord GetCoord(const nsStyleCoord& aCoord, nscoord aIfNotCoord)