1 files changed, 10 insertions, 10 deletions

diff --git a/layout/tables/nsTableWrapperFrame.cpp b/layout/tables/nsTableWrapperFrame.cpp
index da71375d5..86f032218 100644
--- a/layout/tables/nsTableWrapperFrame.cpp
+++ b/layout/tables/nsTableWrapperFrame.cpp
@@ -168,7 +168,6 @@ nsTableWrapperFrame::RemoveFrame(ChildListID  aListID,
 
 void
 nsTableWrapperFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
-                                      const nsRect&           aDirtyRect,
                                       const nsDisplayListSet& aLists)
 {
   // No border, background or outline are painted because they all belong
@@ -177,20 +176,22 @@ nsTableWrapperFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
   // If there's no caption, take a short cut to avoid having to create
   // the special display list set and then sort it.
   if (mCaptionFrames.IsEmpty()) {
-    BuildDisplayListForInnerTable(aBuilder, aDirtyRect, aLists);
+    BuildDisplayListForInnerTable(aBuilder, aLists);
     return;
   }
 
-  nsDisplayListCollection set;
-  BuildDisplayListForInnerTable(aBuilder, aDirtyRect, set);
+  nsDisplayListCollection set(aBuilder);
+  BuildDisplayListForInnerTable(aBuilder, set);
   
   nsDisplayListSet captionSet(set, set.BlockBorderBackgrounds());
-  BuildDisplayListForChild(aBuilder, mCaptionFrames.FirstChild(),
-                           aDirtyRect, captionSet);
+  BuildDisplayListForChild(aBuilder, mCaptionFrames.FirstChild(), captionSet);
 
   // Now we have to sort everything by content order, since the caption
-  // may be somewhere inside the table
-  set.BlockBorderBackgrounds()->SortByContentOrder(GetContent());
+  // may be somewhere inside the table.
+  // We don't sort BlockBorderBackgrounds and BorderBackgrounds because the
+  // display items in those lists should stay out of content order in order to
+  // follow the rules in https://www.w3.org/TR/CSS21/zindex.html#painting-order
+  // and paint the caption background after all of the rest.
   set.Floats()->SortByContentOrder(GetContent());
   set.Content()->SortByContentOrder(GetContent());
   set.PositionedDescendants()->SortByContentOrder(GetContent());
@@ -200,7 +201,6 @@ nsTableWrapperFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
 
 void
 nsTableWrapperFrame::BuildDisplayListForInnerTable(nsDisplayListBuilder*   aBuilder,
-                                                   const nsRect&           aDirtyRect,
                                                    const nsDisplayListSet& aLists)
 {
   // Just paint the regular children, but the children's background is our
@@ -208,7 +208,7 @@ nsTableWrapperFrame::BuildDisplayListForInnerTable(nsDisplayListBuilder*   aBuil
   nsIFrame* kid = mFrames.FirstChild();
   // The children should be in content order
   while (kid) {
-    BuildDisplayListForChild(aBuilder, kid, aDirtyRect, aLists);
+    BuildDisplayListForChild(aBuilder, kid, aLists);
     kid = kid->GetNextSibling();
   }
 }