Bug 1145218 - Make the float manager's writing-mode field debug-only, and assert that it matches what callers are passing in. r=smontagu

layout/generic/nsFloatManager.cpp

@@ -39,7 +39,10 @@ PSArenaFreeCB(size_t aSize, void* aPtr, void* aClosure)
 
 nsFloatManager::nsFloatManager(nsIPresShell* aPresShell,
                                mozilla::WritingMode aWM)
-  : mWritingMode(aWM),
+  :
+#ifdef DEBUG
+    mWritingMode(aWM),
+#endif
     mLineLeft(0), mBlockStart(0),
     mFloatDamage(PSArenaAllocCB, PSArenaFreeCB, aPresShell),
     mPushedLeftFloatPastBreak(false),
@@ -111,12 +114,17 @@ void nsFloatManager::Shutdown()
   sCachedFloatManagerCount = -1;
 }
 
+#define CHECK_BLOCK_DIR(aWM) \
+  NS_ASSERTION(aWM.GetBlockDir() == mWritingMode.value.GetBlockDir(), \
+  "incompatible writing modes")
+
 nsFlowAreaRect
 nsFloatManager::GetFlowArea(WritingMode aWM, nscoord aBOffset,
                             BandInfoType aInfoType, nscoord aBSize,
                             LogicalRect aContentArea, SavedState* aState,
                             nscoord aContainerWidth) const
 {
+  CHECK_BLOCK_DIR(aWM);
   NS_ASSERTION(aBSize >= 0, "unexpected max block size");
   NS_ASSERTION(aContentArea.ISize(aWM) >= 0,
                "unexpected content area inline size");
@@ -246,6 +254,7 @@ nsresult
 nsFloatManager::AddFloat(nsIFrame* aFloatFrame, const LogicalRect& aMarginRect,
                          WritingMode aWM, nscoord aContainerWidth)
 {
+  CHECK_BLOCK_DIR(aWM);
   NS_ASSERTION(aMarginRect.ISize(aWM) >= 0, "negative inline size!");
   NS_ASSERTION(aMarginRect.BSize(aWM) >= 0, "negative block size!");
 
@@ -405,7 +414,6 @@ nsFloatManager::PushState(SavedState* aState)
   // reflow. In the typical case A and C will be the same, but not always.
   // Allowing mFloatDamage to accumulate the damage incurred during both
   // reflows ensures that nothing gets missed.
-  aState->mWritingMode = mWritingMode;
   aState->mLineLeft = mLineLeft;
   aState->mBlockStart = mBlockStart;
   aState->mPushedLeftFloatPastBreak = mPushedLeftFloatPastBreak;
@@ -420,7 +428,6 @@ nsFloatManager::PopState(SavedState* aState)
 {
   NS_PRECONDITION(aState, "No state to restore?");
 
-  mWritingMode = aState->mWritingMode;
   mLineLeft = aState->mLineLeft;
   mBlockStart = aState->mBlockStart;
   mPushedLeftFloatPastBreak = aState->mPushedLeftFloatPastBreak;

layout/generic/nsFloatManager.h

@@ -88,7 +88,6 @@ public:
     explicit SavedState() {}
   private:
     uint32_t mFloatInfoCount;
-    mozilla::WritingMode mWritingMode;
     nscoord mLineLeft, mBlockStart;
     bool mPushedLeftFloatPastBreak;
     bool mPushedRightFloatPastBreak;
@@ -287,8 +286,7 @@ public:
 
   void AssertStateMatches(SavedState *aState) const
   {
-    NS_ASSERTION(aState->mWritingMode == mWritingMode &&
-                 aState->mLineLeft == mLineLeft &&
+    NS_ASSERTION(aState->mLineLeft == mLineLeft &&
                  aState->mBlockStart == mBlockStart &&
                  aState->mPushedLeftFloatPastBreak ==
                    mPushedLeftFloatPastBreak &&
@@ -343,7 +341,7 @@ private:
     nsRect mRect;
   };
 
-  mozilla::WritingMode mWritingMode;
+  mozilla::DebugOnly<mozilla::WritingMode> mWritingMode;
 
   // Translation from local to global coordinate space.
   nscoord mLineLeft, mBlockStart;