Fixed a problem with the method AttributeAffectsStyle: it was erroneously ignoring the fact that HTML attributes can affect style even if there are no CSS rules with thos attributes in the selectors. Changed to restrict the selector evaluation to XML elements. r=shaver, a=karnaze, b=39642

layout/base/nsFrameManager.cpp

@@ -52,6 +52,7 @@
 #include "nsIPresState.h"
 #include "nsIContent.h"
 #include "nsINameSpaceManager.h"
+#include "nsIXMLContent.h"
 
 // Class IID's
 static NS_DEFINE_IID(kEventQueueServiceCID, NS_EVENTQUEUESERVICE_CID);
@@ -1393,11 +1394,20 @@ NS_IMETHODIMP
 FrameManager::AttributeAffectsStyle(nsIAtom *aAttribute, nsIContent *aContent,
                                     PRBool &aAffects)
 {
-  if (aAttribute == nsHTMLAtoms::style) {
+  nsresult rv = NS_OK;
+
+  nsCOMPtr<nsIXMLContent> xml(do_QueryInterface(aContent));
+  if (xml) {
+    rv = mStyleSet->AttributeAffectsStyle(aAttribute, aContent, aAffects);
+  } else {
+    // not an XML element, so assume it is an HTML element and further assume that
+    // any attribute may affect style
+    // NOTE: we could list all of the presentation-hint attributes and check them,
+    //       but there are a lot of them and this is safer.
     aAffects = PR_TRUE;
-    return NS_OK;
+    rv = NS_OK;
   }
-  return mStyleSet->AttributeAffectsStyle(aAttribute, aContent, aAffects);
+  return rv;
 }
 
 static nsresult

layout/html/base/src/nsFrameManager.cpp

@@ -52,6 +52,7 @@
 #include "nsIPresState.h"
 #include "nsIContent.h"
 #include "nsINameSpaceManager.h"
+#include "nsIXMLContent.h"
 
 // Class IID's
 static NS_DEFINE_IID(kEventQueueServiceCID, NS_EVENTQUEUESERVICE_CID);
@@ -1393,11 +1394,20 @@ NS_IMETHODIMP
 FrameManager::AttributeAffectsStyle(nsIAtom *aAttribute, nsIContent *aContent,
                                     PRBool &aAffects)
 {
-  if (aAttribute == nsHTMLAtoms::style) {
+  nsresult rv = NS_OK;
+
+  nsCOMPtr<nsIXMLContent> xml(do_QueryInterface(aContent));
+  if (xml) {
+    rv = mStyleSet->AttributeAffectsStyle(aAttribute, aContent, aAffects);
+  } else {
+    // not an XML element, so assume it is an HTML element and further assume that
+    // any attribute may affect style
+    // NOTE: we could list all of the presentation-hint attributes and check them,
+    //       but there are a lot of them and this is safer.
     aAffects = PR_TRUE;
-    return NS_OK;
+    rv = NS_OK;
   }
-  return mStyleSet->AttributeAffectsStyle(aAttribute, aContent, aAffects);
+  return rv;
 }
 
 static nsresult