Make sure to reframe when the "rules" attribute changes, since tables cache all

sorts of border-collapse stuff across reflows.  Bug 226593, r=bernd, sr=dbaron,
a=brendan

content/html/content/src/nsHTMLTableElement.cpp

@@ -1487,9 +1487,6 @@ nsHTMLTableElement::HasAttributeDependentStyle(const nsIAtom* aAttribute) const
     
     { &nsHTMLAtoms::bordercolor },
     
-    // Changing to rules will force border-collapse. Unfortunately, if
-    // border-collapse was already in effect, then a frame change is
-    // not necessary.
     { &nsHTMLAtoms::align },
     { &nsHTMLAtoms::rules },
     { nsnull }

content/shared/src/nsStyleStruct.cpp

@@ -875,9 +875,12 @@ nsStyleTable::nsStyleTable(const nsStyleTable& aSource)
 
 nsChangeHint nsStyleTable::CalcDifference(const nsStyleTable& aOther) const
 {
+  // Changes in mRules may require reframing (if border-collapse stuff changes, for example).
+  if (mRules != aOther.mRules)
+    return NS_STYLE_HINT_FRAMECHANGE;
+
   if ((mLayoutStrategy == aOther.mLayoutStrategy) &&
       (mFrame == aOther.mFrame) &&
-      (mRules == aOther.mRules) &&
       (mCols == aOther.mCols) &&
       (mSpan == aOther.mSpan))
     return NS_STYLE_HINT_NONE;

layout/style/nsStyleStruct.cpp

@@ -875,9 +875,12 @@ nsStyleTable::nsStyleTable(const nsStyleTable& aSource)
 
 nsChangeHint nsStyleTable::CalcDifference(const nsStyleTable& aOther) const
 {
+  // Changes in mRules may require reframing (if border-collapse stuff changes, for example).
+  if (mRules != aOther.mRules)
+    return NS_STYLE_HINT_FRAMECHANGE;
+
   if ((mLayoutStrategy == aOther.mLayoutStrategy) &&
       (mFrame == aOther.mFrame) &&
-      (mRules == aOther.mRules) &&
       (mCols == aOther.mCols) &&
       (mSpan == aOther.mSpan))
     return NS_STYLE_HINT_NONE;