1) Added sanity checks to box to case memory bugs

2) Fixed the floating point roundoff that was causing boxes to lay themselves out off by 1 pixel
3) Simplified box data structure

-r Hyatt

layout/generic/nsGfxScrollFrame.cpp

@@ -1599,7 +1599,7 @@ nsGfxScrollFrameInner::GetIntegerAttribute(nsIFrame* aFrame, nsIAtom* atom, PRIn
 NS_IMETHODIMP
 nsGfxScrollFrame::GetBoxInfo(nsIPresContext* aPresContext, const nsHTMLReflowState& aReflowState, nsBoxInfo& aSize)
 {
-  aSize.clear();
+  aSize.Clear();
 
   nsresult rv;
   nsBoxInfo scrollAreaInfo, vboxInfo, hboxInfo;

layout/html/base/src/nsGfxScrollFrame.cpp

@@ -1599,7 +1599,7 @@ nsGfxScrollFrameInner::GetIntegerAttribute(nsIFrame* aFrame, nsIAtom* atom, PRIn
 NS_IMETHODIMP
 nsGfxScrollFrame::GetBoxInfo(nsIPresContext* aPresContext, const nsHTMLReflowState& aReflowState, nsBoxInfo& aSize)
 {
-  aSize.clear();
+  aSize.Clear();
 
   nsresult rv;
   nsBoxInfo scrollAreaInfo, vboxInfo, hboxInfo;

layout/html/base/src/nsScrollPortFrame.cpp

@@ -541,7 +541,7 @@ nsScrollPortFrame::GetBoxInfo(nsIPresContext* aPresContext, const nsHTMLReflowSt
 {
    nsresult rv;
 
-   aSize.clear();
+   aSize.Clear();
  
    if (mNeedsRecalc) {
        nsIFrame* childFrame = mFrames.FirstChild(); 
@@ -595,7 +595,7 @@ nsScrollPortFrame::GetBoxInfo(nsIPresContext* aPresContext, const nsHTMLReflowSt
 nsresult
 nsScrollPortFrame::GetChildBoxInfo(nsIPresContext* aPresContext, const nsHTMLReflowState& aReflowState, nsIFrame* aFrame, nsBoxInfo& aSize)
 {
-  aSize.clear();
+  aSize.Clear();
 
   // see if the frame has IBox interface
 

layout/xul/base/src/nsBoxFrame.h

@@ -51,7 +51,9 @@ public:
     PRBool isIncremental;
     nsHTMLInfo* htmlInfo;
     nsCalculatedBoxInfo* next;
-    virtual void clear()=0;
+    nsIFrame* frame;
+    PRBool prefWidthIntrinsic;
+    PRBool prefHeightIntrinsic;
 };
 
 class nsInfoList 
@@ -130,11 +132,10 @@ public:
                           nsIAtom*        aListName,
                           nsIFrame*       aOldFrame);
 
-  NS_IMETHOD ReplaceFrame(nsIPresContext* aPresContext,
-                          nsIPresShell&   aPresShell,
-                          nsIAtom*        aListName,
-                          nsIFrame*       aOldFrame,
-                          nsIFrame*       aNewFrame);
+  NS_IMETHOD  SetInitialChildList(nsIPresContext* aPresContext,
+                                  nsIAtom*        aListName,
+                                  nsIFrame*       aChildList);
+
 
   NS_IMETHOD GetFrameName(nsString& aResult) const;
 

layout/xul/base/src/nsIBox.h

@@ -45,26 +45,11 @@ public:
     nsSize prefSize;
     nsSize minSize;
     nsSize maxSize; 
+    PRInt32 flex;
 
-    float flex;
-
-    nsBoxInfo() { clear(); }
-
-    virtual void clear()
-    {
-      prefSize.width = 0;
-      prefSize.height = 0;
-
-      minSize.width = 0;
-      minSize.height = 0;
-
-      flex = 0.0;
-
-      maxSize.width = NS_INTRINSICSIZE;
-      maxSize.height = NS_INTRINSICSIZE;
-    }
-
-    virtual ~nsBoxInfo() {}
+    nsBoxInfo();
+    virtual void Clear();
+    virtual ~nsBoxInfo();
   
 };
 

layout/xul/base/src/nsTitledButtonFrame.cpp

@@ -933,7 +933,7 @@ nsTitledButtonFrame::GetDesiredSize(nsIPresContext* aPresContext,
 {
   // get our info object.
   nsBoxInfo info;
-  info.clear();
+  info.Clear();
 
   GetBoxInfo(aPresContext, aReflowState, info);