2 files changed, 112 insertions, 4 deletions

diff --git a/layout/tables/nsTableFrame.cpp b/layout/tables/nsTableFrame.cpp
index 4257c9c57..e5a48139a 100644
--- a/layout/tables/nsTableFrame.cpp
+++ b/layout/tables/nsTableFrame.cpp
@@ -1268,6 +1268,74 @@ PaintRowGroupBackgroundByColIdx(nsTableRowGroupFrame* aRowGroup,
   }
 }
 
+static inline bool FrameHasBorder(nsIFrame* f)
+{
+  if (!f->StyleVisibility()->IsVisible()) {
+    return false;
+  }
+
+  if (f->StyleBorder()->HasBorder()) {
+    return true;
+  }
+
+  return false;
+}
+
+void nsTableFrame::CalcHasBCBorders()
+{
+  if (!IsBorderCollapse()) {
+    SetHasBCBorders(false);
+    return;
+  }
+
+  if (FrameHasBorder(this)) {
+    SetHasBCBorders(true);
+    return;
+  }
+
+  // Check col and col group has borders.
+  for (nsIFrame* f : this->GetChildList(kColGroupList)) {
+    if (FrameHasBorder(f)) {
+      SetHasBCBorders(true);
+      return;
+    }
+
+    nsTableColGroupFrame *colGroup = static_cast<nsTableColGroupFrame*>(f);
+    for (nsTableColFrame* col = colGroup->GetFirstColumn(); col; col = col->GetNextCol()) {
+      if (FrameHasBorder(col)) {
+        SetHasBCBorders(true);
+        return;
+      }
+    }
+  }
+
+  // check row group, row and cell has borders.
+  RowGroupArray rowGroups;
+  OrderRowGroups(rowGroups);
+  for (nsTableRowGroupFrame* rowGroup : rowGroups) {
+    if (FrameHasBorder(rowGroup)) {
+      SetHasBCBorders(true);
+      return;
+    }
+
+    for (nsTableRowFrame* row = rowGroup->GetFirstRow(); row; row = row->GetNextRow()) {
+      if (FrameHasBorder(row)) {
+        SetHasBCBorders(true);
+        return;
+      }
+
+      for (nsTableCellFrame* cell = row->GetFirstCell(); cell; cell = cell->GetNextCell()) {
+        if (FrameHasBorder(cell)) {
+          SetHasBCBorders(true);
+          return;
+        }
+      }
+    }
+  }
+
+  SetHasBCBorders(false);
+}
+
 /* static */ void
 nsTableFrame::DisplayGenericTablePart(nsDisplayListBuilder* aBuilder,
                                       nsFrame* aFrame,
@@ -1375,11 +1443,16 @@ nsTableFrame::DisplayGenericTablePart(nsDisplayListBuilder* aBuilder,
       nsTableFrame* table = static_cast<nsTableFrame*>(aFrame);
       // In the collapsed border model, overlay all collapsed borders.
       if (table->IsBorderCollapse()) {
-        aLists.BorderBackground()->AppendNewToTop(
-          new (aBuilder) nsDisplayTableBorderCollapse(aBuilder, table));
+        if (table->HasBCBorders()) {
+          aLists.BorderBackground()->AppendNewToTop(
+            new (aBuilder) nsDisplayTableBorderCollapse(aBuilder, table));
+        }
       } else {
-        aLists.BorderBackground()->AppendNewToTop(
-          new (aBuilder) nsDisplayBorder(aBuilder, table));
+        const nsStyleBorder* borderStyle = aFrame->StyleBorder();
+        if (borderStyle->HasBorder()) {
+          aLists.BorderBackground()->AppendNewToTop(
+            new (aBuilder) nsDisplayBorder(aBuilder, table));
+        }
       }
     }
   }
@@ -4101,6 +4174,7 @@ nsTableFrame::AddBCDamageArea(const TableArea& aValue)
 #endif
 
   SetNeedToCalcBCBorders(true);
+  SetNeedToCalcHasBCBorders(true);
   // Get the property
   BCPropertyData* value = GetOrCreateBCProperty();
   if (value) {
@@ -4141,6 +4215,7 @@ nsTableFrame::SetFullBCDamageArea()
   NS_ASSERTION(IsBorderCollapse(), "invalid SetFullBCDamageArea call");
 
   SetNeedToCalcBCBorders(true);
+  SetNeedToCalcHasBCBorders(true);
 
   BCPropertyData* value = GetOrCreateBCProperty();
   if (value) {
diff --git a/layout/tables/nsTableFrame.h b/layout/tables/nsTableFrame.h
index a6b786402..d739faa72 100644
--- a/layout/tables/nsTableFrame.h
+++ b/layout/tables/nsTableFrame.h
@@ -761,6 +761,13 @@ public:
   bool NeedToCollapse() const;
   void SetNeedToCollapse(bool aValue);
 
+  bool NeedToCalcHasBCBorders() const;
+  void SetNeedToCalcHasBCBorders(bool aValue);
+
+  void CalcHasBCBorders();
+  bool HasBCBorders();
+  void SetHasBCBorders(bool aValue);
+
   /** The GeometryDirty bit is similar to the NS_FRAME_IS_DIRTY frame
     * state bit, which implies that all descendants are dirty.  The
     * GeometryDirty still implies that all the parts of the table are
@@ -870,6 +877,8 @@ protected:
     uint32_t mIStartContBCBorder:8;
     uint32_t mNeedToCollapse:1;        // rows, cols that have visibility:collapse need to be collapsed
     uint32_t mResizedColumns:1;        // have we resized columns since last reflow?
+    uint32_t mNeedToCalcHasBCBorders:1;
+    uint32_t mHasBCBorders:1;
   } mBits;
 
   nsTableCellMap*         mCellMap;            // maintains the relationships between rows, cols, and cells
@@ -965,6 +974,30 @@ inline void nsTableFrame::SetNeedToCalcBCBorders(bool aValue)
   mBits.mNeedToCalcBCBorders = (unsigned)aValue;
 }
 
+inline bool nsTableFrame::NeedToCalcHasBCBorders() const
+{
+  return (bool)mBits.mNeedToCalcHasBCBorders;
+}
+
+inline void nsTableFrame::SetNeedToCalcHasBCBorders(bool aValue)
+{
+  mBits.mNeedToCalcHasBCBorders = (unsigned)aValue;
+}
+
+inline bool nsTableFrame::HasBCBorders()
+{
+  if (NeedToCalcHasBCBorders()) {
+    CalcHasBCBorders();
+    SetNeedToCalcHasBCBorders(false);
+  }
+  return (bool)mBits.mHasBCBorders;
+}
+
+inline void nsTableFrame::SetHasBCBorders(bool aValue)
+{
+  mBits.mHasBCBorders = (unsigned)aValue;
+}
+
 inline nscoord
 nsTableFrame::GetContinuousIStartBCBorderWidth() const
 {