Bug 998535 - Apply GetSkipSides to block border+padding to make it for work for box-decoration-break:clone. r=roc

layout/generic/nsBlockReflowState.cpp

@@ -46,14 +46,14 @@ nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState,
   SetFlag(BRS_ISOVERFLOWCONTAINER,
           IS_TRUE_OVERFLOW_CONTAINER(aFrame));
 
-  const nsMargin& borderPadding = BorderPadding();
-  mContainerWidth = aReflowState.ComputedWidth() +
-                    aReflowState.ComputedPhysicalBorderPadding().LeftRight();
+  mBorderPadding = mReflowState.ComputedPhysicalBorderPadding();
+  aFrame->ApplySkipSides(mBorderPadding, &aReflowState);
+  mContainerWidth = aReflowState.ComputedWidth() + mBorderPadding.LeftRight();
 
-  if (aTopMarginRoot || 0 != aReflowState.ComputedPhysicalBorderPadding().top) {
+  if (aTopMarginRoot || 0 != mBorderPadding.top) {
     SetFlag(BRS_ISTOPMARGINROOT, true);
   }
-  if (aBottomMarginRoot || 0 != aReflowState.ComputedPhysicalBorderPadding().bottom) {
+  if (aBottomMarginRoot || 0 != mBorderPadding.bottom) {
     SetFlag(BRS_ISBOTTOMMARGINROOT, true);
   }
   if (GetFlag(BRS_ISTOPMARGINROOT)) {
@@ -93,8 +93,8 @@ nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState,
     // We are in a paginated situation. The bottom edge is just inside
     // the bottom border and padding. The content area height doesn't
     // include either border or padding edge.
-    mBottomEdge = aReflowState.AvailableHeight() - borderPadding.bottom;
-    mContentArea.height = std::max(0, mBottomEdge - borderPadding.top);
+    mBottomEdge = aReflowState.AvailableHeight() - mBorderPadding.bottom;
+    mContentArea.height = std::max(0, mBottomEdge - mBorderPadding.top);
   }
   else {
     // When we are not in a paginated situation then we always use
@@ -102,8 +102,8 @@ nsBlockReflowState::nsBlockReflowState(const nsHTMLReflowState& aReflowState,
     SetFlag(BRS_UNCONSTRAINEDHEIGHT, true);
     mContentArea.height = mBottomEdge = NS_UNCONSTRAINEDSIZE;
   }
-  mContentArea.x = borderPadding.left;
-  mY = mContentArea.y = borderPadding.top;
+  mContentArea.x = mBorderPadding.left;
+  mY = mContentArea.y = mBorderPadding.top;
 
   mPrevChild = nullptr;
   mCurrentLine = aFrame->end_lines();

layout/generic/nsBlockReflowState.h

@@ -92,23 +92,14 @@ public:
                       uint32_t aFlags = 0);
 
   bool IsAdjacentWithTop() const {
-    return mY ==
-      ((mFlags & BRS_ISFIRSTINFLOW) ? mReflowState.ComputedPhysicalBorderPadding().top : 0);
+    return mY == mBorderPadding.top;
   }
 
   /**
-   * Adjusts the border/padding to return 0 for the top if
-   * we are not the first in flow.
+   * Return mBlock's computed physical border+padding with GetSkipSides applied.
    */
-  nsMargin BorderPadding() const {
-    nsMargin result = mReflowState.ComputedPhysicalBorderPadding();
-    if (!(mFlags & BRS_ISFIRSTINFLOW)) {
-      result.top = 0;
-      if (mFlags & BRS_ISOVERFLOWCONTAINER) {
-        result.bottom = 0;
-      }
-    }
-    return result;
+  const nsMargin& BorderPadding() const {
+    return mBorderPadding;
   }
 
   /**
@@ -222,6 +213,9 @@ public:
   // The current Y coordinate in the block
   nscoord mY;
 
+  // mBlock's computed physical border+padding with GetSkipSides applied.
+  nsMargin mBorderPadding;
+
   // The overflow areas of all floats placed so far
   nsOverflowAreas mFloatOverflowAreas;