Columns should invalidate the tree when their width changes, not just when

attributes that affect width change.  Bug 257237, r=varga, sr=roc

layout/xul/base/src/tree/src/nsTreeColFrame.cpp

@@ -191,7 +191,24 @@ nsTreeColFrame::AttributeChanged(nsPresContext* aPresContext,
                                              aNameSpaceID, aAttribute,
                                              aModType);
 
-  if (aAttribute == nsHTMLAtoms::width || aAttribute == nsHTMLAtoms::hidden) {
+  if (aAttribute == nsXULAtoms::ordinal || aAttribute == nsXULAtoms::primary) {
+    EnsureColumns();
+    if (mColumns)
+      mColumns->InvalidateColumns();
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsTreeColFrame::SetBounds(nsBoxLayoutState& aBoxLayoutState,
+                          const nsRect& aRect,
+                          PRBool aRemoveOverflowArea) {
+  nscoord oldWidth = mRect.width;
+
+  nsresult rv = nsBoxFrame::SetBounds(aBoxLayoutState, aRect,
+                                      aRemoveOverflowArea);
+  if (mRect.width != oldWidth) {
     EnsureColumns();
     if (mColumns) {
       nsCOMPtr<nsITreeBoxObject> tree;
@@ -200,12 +217,6 @@ nsTreeColFrame::AttributeChanged(nsPresContext* aPresContext,
         tree->Invalidate();
     }
   }
-  else if (aAttribute == nsXULAtoms::ordinal || aAttribute == nsXULAtoms::primary) {
-    EnsureColumns();
-    if (mColumns)
-      mColumns->InvalidateColumns();
-  }
-
   return rv;
 }
 

layout/xul/base/src/tree/src/nsTreeColFrame.h

@@ -69,6 +69,9 @@ public:
                               nsIAtom* aAttribute,
                               PRInt32 aModType);
 
+  NS_IMETHOD SetBounds(nsBoxLayoutState& aBoxLayoutState, const nsRect& aRect,
+                       PRBool aRemoveOverflowArea = PR_FALSE);
+
   friend nsresult NS_NewTreeColFrame(nsIPresShell* aPresShell, 
                                      nsIFrame** aNewFrame, 
                                      PRBool aIsRoot,