diff --git a/mozilla/content/base/src/nsDocument.cpp b/mozilla/content/base/src/nsDocument.cpp
index 9c05db55352..98eba614468 100644
--- a/mozilla/content/base/src/nsDocument.cpp
+++ b/mozilla/content/base/src/nsDocument.cpp
@@ -80,7 +80,6 @@
 #include "nsIScrollableView.h"
 #include "nsIPresShell.h"
 #include "nsIPresContext.h"
-#include "nsStyleSet.h"
 #include "nsContentUtils.h"
 #include "nsNodeInfoManager.h"
 #include "nsIXBLService.h"
@@ -758,6 +757,8 @@ nsresult
 nsDocument::ResetStylesheetsToURI(nsIURI* aURI)
 {
   NS_PRECONDITION(aURI, "Null URI passed to ResetStylesheetsToURI");
+
+  mozAutoDocUpdate(this, UPDATE_STYLE, PR_TRUE);
   
   // The stylesheets should forget us
   PRInt32 indx = mStyleSheets.Count();
@@ -781,15 +782,34 @@ nsDocument::ResetStylesheetsToURI(nsIURI* aURI)
   // already set their owning document to null in the loop above, but
   // we'll reset it when we call AddStyleSheet on them.
   nsresult rv;
+  nsStyleSet::sheetType attrSheetType = GetAttrSheetType();
   if (mAttrStyleSheet) {
+    // Remove this sheet from all style sets
+    PRInt32 count = mPresShells.Count();
+    for (indx = 0; indx < count; ++indx) {
+      NS_STATIC_CAST(nsIPresShell*, mPresShells.ElementAt(indx))->StyleSet()->
+        RemoveStyleSheet(attrSheetType, mAttrStyleSheet);
+    }
     rv = mAttrStyleSheet->Reset(aURI);
   } else {
     rv = NS_NewHTMLStyleSheet(getter_AddRefs(mAttrStyleSheet), aURI, this);
   }
   NS_ENSURE_SUCCESS(rv, rv);
-  
-  AddStyleSheet(mAttrStyleSheet, 0);
 
+  // Add mAttrStyleSheet to all the style sets.  Prepend it, since it should be
+  // the most significant sheet in its level (whether UA or preshint).
+  PRInt32 count = mPresShells.Count();
+  for (indx = 0; indx < count; ++indx) {
+    NS_STATIC_CAST(nsIPresShell*, mPresShells.ElementAt(indx))->StyleSet()->
+      PrependStyleSheet(attrSheetType, mAttrStyleSheet);
+  }
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Don't use AddStyleSheet, since it'll put the sheet into style
+  // sets in the document level, which is not desirable here.
+  InternalAddStyleSheet(mAttrStyleSheet, 0);
+  mAttrStyleSheet->SetOwningDocument(this);
+  
   if (mStyleAttrStyleSheet) {
     rv = mStyleAttrStyleSheet->Reset(aURI);
   } else {
@@ -803,6 +823,12 @@ nsDocument::ResetStylesheetsToURI(nsIURI* aURI)
   return rv;
 }
 
+nsStyleSet::sheetType
+nsDocument::GetAttrSheetType()
+{
+  return nsStyleSet::eAgentSheet;
+}
+
 nsresult
 nsDocument::StartDocumentLoad(const char* aCommand, nsIChannel* aChannel,
                               nsILoadGroup* aLoadGroup,
diff --git a/mozilla/content/base/src/nsDocument.h b/mozilla/content/base/src/nsDocument.h
index bcff4b5bf5e..f666ed24ef4 100644
--- a/mozilla/content/base/src/nsDocument.h
+++ b/mozilla/content/base/src/nsDocument.h
@@ -83,6 +83,8 @@
 #include "nsHTMLStyleSheet.h"
 #include "nsIHTMLCSSStyleSheet.h"
 
+#include "nsStyleSet.h"
+
 #include "pldhash.h"
 
 
@@ -100,7 +102,6 @@ class nsIDTD;
 class nsXPathDocumentTearoff;
 class nsIRadioVisitor;
 class nsIFormControl;
-class nsStyleSet;
 struct nsRadioGroupStruct;
 
 
@@ -511,6 +512,7 @@ protected:
                          nsIPresShell** aInstancePtrResult);
 
   nsresult ResetStylesheetsToURI(nsIURI* aURI);
+  virtual nsStyleSet::sheetType GetAttrSheetType();
 
   nsresult CreateElement(nsINodeInfo *aNodeInfo, nsIDOMElement** aResult);
 
diff --git a/mozilla/content/base/src/nsStyleSet.cpp b/mozilla/content/base/src/nsStyleSet.cpp
index 6484cef4133..7de859757fd 100644
--- a/mozilla/content/base/src/nsStyleSet.cpp
+++ b/mozilla/content/base/src/nsStyleSet.cpp
@@ -416,7 +416,13 @@ nsStyleSet::FileRules(nsIStyleRuleProcessor::EnumFunc aCollectorFunc,
     lastUserRN = mRuleWalker->GetCurrentNode();
   }
 
-  nsRuleNode* lastDocRN = lastUserRN;
+  nsRuleNode* lastPresHintRN = lastUserRN;
+  if (mRuleProcessors[ePresHintSheet].Count()) {
+    mRuleProcessors[ePresHintSheet].EnumerateForwards(aCollectorFunc, aData);
+    lastPresHintRN = mRuleWalker->GetCurrentNode();
+  }
+  
+  nsRuleNode* lastDocRN = lastPresHintRN;
   PRBool useRuleProcessors = PR_TRUE;
   if (mStyleRuleSupplier) {
     // We can supply additional document-level sheets that should be walked.
@@ -436,6 +442,7 @@ nsStyleSet::FileRules(nsIStyleRuleProcessor::EnumFunc aCollectorFunc,
 
   AddImportantRules(lastDocRN, lastUserRN);   //doc
   AddImportantRules(lastOvrRN, lastDocRN);    //ovr
+  // There should be no imporant rules in the preshint level
   AddImportantRules(lastUserRN, lastAgentRN); //user
   AddImportantRules(lastAgentRN, nsnull);     //agent
 
@@ -453,6 +460,9 @@ nsStyleSet::WalkRuleProcessors(nsIStyleRuleProcessor::EnumFunc aFunc,
   // Walk the user rules next.
   mRuleProcessors[eUserSheet].EnumerateForwards(aFunc, aData);
 
+  // Walk preshint rules.
+  mRuleProcessors[ePresHintSheet].EnumerateForwards(aFunc, aData);
+  
   PRBool useRuleProcessors = PR_TRUE;
   if (mStyleRuleSupplier) {
     // We can supply additional document-level sheets that should be walked.
@@ -513,9 +523,10 @@ nsStyleSet::ResolveStyleFor(nsIContent* aContent,
                "content must be element");
 
   if (aContent && presContext) {
-    if (mRuleProcessors[eAgentSheet].Count() ||
-        mRuleProcessors[eUserSheet].Count()  ||
-        mRuleProcessors[eDocSheet].Count()   ||
+    if (mRuleProcessors[eAgentSheet].Count()    ||
+        mRuleProcessors[eUserSheet].Count()     ||
+        mRuleProcessors[ePresHintSheet].Count() ||
+        mRuleProcessors[eDocSheet].Count()      ||
         mRuleProcessors[eOverrideSheet].Count()) {
       RulesMatchingData data(presContext, aContent, mRuleWalker);
       FileRules(EnumRulesMatching, &data);
@@ -536,9 +547,10 @@ nsStyleSet::ResolveStyleForNonElement(nsStyleContext* aParentContext)
   nsIPresContext *presContext = PresContext();
 
   if (presContext) {
-    if (mRuleProcessors[eAgentSheet].Count() ||
-        mRuleProcessors[eUserSheet].Count()  ||
-        mRuleProcessors[eDocSheet].Count()   ||
+    if (mRuleProcessors[eAgentSheet].Count()    ||
+        mRuleProcessors[eUserSheet].Count()     ||
+        mRuleProcessors[ePresHintSheet].Count() ||
+        mRuleProcessors[eDocSheet].Count()      ||
         mRuleProcessors[eOverrideSheet].Count()) {
       result = GetContext(presContext, aParentContext,
                           nsCSSAnonBoxes::mozNonElement).get();
@@ -588,9 +600,10 @@ nsStyleSet::ResolvePseudoStyleFor(nsIContent* aParentContent,
                "content (if non-null) must be element");
 
   if (aPseudoTag && presContext) {
-    if (mRuleProcessors[eAgentSheet].Count() ||
-        mRuleProcessors[eUserSheet].Count()  ||
-        mRuleProcessors[eDocSheet].Count()   ||
+    if (mRuleProcessors[eAgentSheet].Count()    ||
+        mRuleProcessors[eUserSheet].Count()     ||
+        mRuleProcessors[ePresHintSheet].Count() ||
+        mRuleProcessors[eDocSheet].Count()      ||
         mRuleProcessors[eOverrideSheet].Count()) {
       PseudoRulesMatchingData data(presContext, aParentContent, aPseudoTag,
                                    aComparator, mRuleWalker);
@@ -620,9 +633,10 @@ nsStyleSet::ProbePseudoStyleFor(nsIContent* aParentContent,
                "content (if non-null) must be element");
 
   if (aPseudoTag && presContext) {
-    if (mRuleProcessors[eAgentSheet].Count() ||
-        mRuleProcessors[eUserSheet].Count()  ||
-        mRuleProcessors[eDocSheet].Count()   ||
+    if (mRuleProcessors[eAgentSheet].Count()    ||
+        mRuleProcessors[eUserSheet].Count()     ||
+        mRuleProcessors[ePresHintSheet].Count() ||
+        mRuleProcessors[eDocSheet].Count()      ||
         mRuleProcessors[eOverrideSheet].Count()) {
       PseudoRulesMatchingData data(presContext, aParentContent, aPseudoTag,
                                    nsnull, mRuleWalker);
@@ -777,9 +791,10 @@ nsStyleSet::HasStateDependentStyle(nsIPresContext* aPresContext,
   nsReStyleHint result = nsReStyleHint(0);
 
   if (aContent->IsContentOfType(nsIContent::eELEMENT) &&
-      (mRuleProcessors[eAgentSheet].Count() ||
-       mRuleProcessors[eUserSheet].Count()  ||
-       mRuleProcessors[eDocSheet].Count()   ||
+      (mRuleProcessors[eAgentSheet].Count()    ||
+       mRuleProcessors[eUserSheet].Count()     ||
+       mRuleProcessors[ePresHintSheet].Count() ||
+       mRuleProcessors[eDocSheet].Count()      ||
        mRuleProcessors[eOverrideSheet].Count())) {  
     StatefulData data(aPresContext, aContent, aStateMask);
     WalkRuleProcessors(SheetHasStatefulStyle, &data);
@@ -820,9 +835,10 @@ nsStyleSet::HasAttributeDependentStyle(nsIPresContext* aPresContext,
   nsReStyleHint result = nsReStyleHint(0);
 
   if (aContent->IsContentOfType(nsIContent::eELEMENT) &&
-      (mRuleProcessors[eAgentSheet].Count() ||
-       mRuleProcessors[eUserSheet].Count()  ||
-       mRuleProcessors[eDocSheet].Count()   ||
+      (mRuleProcessors[eAgentSheet].Count()     ||
+       mRuleProcessors[eUserSheet].Count()      ||
+       mRuleProcessors[ePresHintSheet].Count()  ||
+       mRuleProcessors[eDocSheet].Count()       ||
        mRuleProcessors[eOverrideSheet].Count())) {  
     AttributeData data(aPresContext, aContent, aAttribute, aModType);
     WalkRuleProcessors(SheetHasAttributeStyle, &data);
diff --git a/mozilla/content/base/src/nsStyleSet.h b/mozilla/content/base/src/nsStyleSet.h
index e9c6f67ff3c..2548da5d535 100644
--- a/mozilla/content/base/src/nsStyleSet.h
+++ b/mozilla/content/base/src/nsStyleSet.h
@@ -155,6 +155,7 @@ class nsStyleSet
   enum sheetType {
     eAgentSheet,
     eUserSheet,
+    ePresHintSheet,
     eDocSheet,
     eOverrideSheet,
     eSheetTypeCount
diff --git a/mozilla/content/html/document/src/nsHTMLDocument.cpp b/mozilla/content/html/document/src/nsHTMLDocument.cpp
index 72db4487aa0..20ae270c0cd 100644
--- a/mozilla/content/html/document/src/nsHTMLDocument.cpp
+++ b/mozilla/content/html/document/src/nsHTMLDocument.cpp
@@ -392,6 +392,15 @@ nsHTMLDocument::ResetToURI(nsIURI *aURI, nsILoadGroup *aLoadGroup)
   mContentType = "text/html";
 }
 
+nsStyleSet::sheetType
+nsHTMLDocument::GetAttrSheetType()
+{
+  if (IsXHTML()) {
+    return nsDocument::GetAttrSheetType();
+  }
+  
+  return nsStyleSet::ePresHintSheet;
+}
 
 nsresult
 nsHTMLDocument::CreateShell(nsIPresContext* aContext,
diff --git a/mozilla/content/html/document/src/nsHTMLDocument.h b/mozilla/content/html/document/src/nsHTMLDocument.h
index 106ef922324..7afc447573e 100644
--- a/mozilla/content/html/document/src/nsHTMLDocument.h
+++ b/mozilla/content/html/document/src/nsHTMLDocument.h
@@ -85,6 +85,7 @@ public:
 
   virtual void Reset(nsIChannel* aChannel, nsILoadGroup* aLoadGroup);
   virtual void ResetToURI(nsIURI* aURI, nsILoadGroup* aLoadGroup);
+  virtual nsStyleSet::sheetType GetAttrSheetType();
 
   virtual nsresult CreateShell(nsIPresContext* aContext,
                                nsIViewManager* aViewManager,
diff --git a/mozilla/content/xml/document/src/Makefile.in b/mozilla/content/xml/document/src/Makefile.in
index f5591829c8e..fe6e774baf1 100644
--- a/mozilla/content/xml/document/src/Makefile.in
+++ b/mozilla/content/xml/document/src/Makefile.in
@@ -67,6 +67,7 @@ REQUIRES	= xpcom \
 		  mimetype \
 		  unicharutil \
 		  windowwatcher \
+		  locale \
 		  $(NULL)
 
 CPPSRCS		= \
diff --git a/mozilla/layout/style/nsStyleSet.cpp b/mozilla/layout/style/nsStyleSet.cpp
index 6484cef4133..7de859757fd 100644
--- a/mozilla/layout/style/nsStyleSet.cpp
+++ b/mozilla/layout/style/nsStyleSet.cpp
@@ -416,7 +416,13 @@ nsStyleSet::FileRules(nsIStyleRuleProcessor::EnumFunc aCollectorFunc,
     lastUserRN = mRuleWalker->GetCurrentNode();
   }
 
-  nsRuleNode* lastDocRN = lastUserRN;
+  nsRuleNode* lastPresHintRN = lastUserRN;
+  if (mRuleProcessors[ePresHintSheet].Count()) {
+    mRuleProcessors[ePresHintSheet].EnumerateForwards(aCollectorFunc, aData);
+    lastPresHintRN = mRuleWalker->GetCurrentNode();
+  }
+  
+  nsRuleNode* lastDocRN = lastPresHintRN;
   PRBool useRuleProcessors = PR_TRUE;
   if (mStyleRuleSupplier) {
     // We can supply additional document-level sheets that should be walked.
@@ -436,6 +442,7 @@ nsStyleSet::FileRules(nsIStyleRuleProcessor::EnumFunc aCollectorFunc,
 
   AddImportantRules(lastDocRN, lastUserRN);   //doc
   AddImportantRules(lastOvrRN, lastDocRN);    //ovr
+  // There should be no imporant rules in the preshint level
   AddImportantRules(lastUserRN, lastAgentRN); //user
   AddImportantRules(lastAgentRN, nsnull);     //agent
 
@@ -453,6 +460,9 @@ nsStyleSet::WalkRuleProcessors(nsIStyleRuleProcessor::EnumFunc aFunc,
   // Walk the user rules next.
   mRuleProcessors[eUserSheet].EnumerateForwards(aFunc, aData);
 
+  // Walk preshint rules.
+  mRuleProcessors[ePresHintSheet].EnumerateForwards(aFunc, aData);
+  
   PRBool useRuleProcessors = PR_TRUE;
   if (mStyleRuleSupplier) {
     // We can supply additional document-level sheets that should be walked.
@@ -513,9 +523,10 @@ nsStyleSet::ResolveStyleFor(nsIContent* aContent,
                "content must be element");
 
   if (aContent && presContext) {
-    if (mRuleProcessors[eAgentSheet].Count() ||
-        mRuleProcessors[eUserSheet].Count()  ||
-        mRuleProcessors[eDocSheet].Count()   ||
+    if (mRuleProcessors[eAgentSheet].Count()    ||
+        mRuleProcessors[eUserSheet].Count()     ||
+        mRuleProcessors[ePresHintSheet].Count() ||
+        mRuleProcessors[eDocSheet].Count()      ||
         mRuleProcessors[eOverrideSheet].Count()) {
       RulesMatchingData data(presContext, aContent, mRuleWalker);
       FileRules(EnumRulesMatching, &data);
@@ -536,9 +547,10 @@ nsStyleSet::ResolveStyleForNonElement(nsStyleContext* aParentContext)
   nsIPresContext *presContext = PresContext();
 
   if (presContext) {
-    if (mRuleProcessors[eAgentSheet].Count() ||
-        mRuleProcessors[eUserSheet].Count()  ||
-        mRuleProcessors[eDocSheet].Count()   ||
+    if (mRuleProcessors[eAgentSheet].Count()    ||
+        mRuleProcessors[eUserSheet].Count()     ||
+        mRuleProcessors[ePresHintSheet].Count() ||
+        mRuleProcessors[eDocSheet].Count()      ||
         mRuleProcessors[eOverrideSheet].Count()) {
       result = GetContext(presContext, aParentContext,
                           nsCSSAnonBoxes::mozNonElement).get();
@@ -588,9 +600,10 @@ nsStyleSet::ResolvePseudoStyleFor(nsIContent* aParentContent,
                "content (if non-null) must be element");
 
   if (aPseudoTag && presContext) {
-    if (mRuleProcessors[eAgentSheet].Count() ||
-        mRuleProcessors[eUserSheet].Count()  ||
-        mRuleProcessors[eDocSheet].Count()   ||
+    if (mRuleProcessors[eAgentSheet].Count()    ||
+        mRuleProcessors[eUserSheet].Count()     ||
+        mRuleProcessors[ePresHintSheet].Count() ||
+        mRuleProcessors[eDocSheet].Count()      ||
         mRuleProcessors[eOverrideSheet].Count()) {
       PseudoRulesMatchingData data(presContext, aParentContent, aPseudoTag,
                                    aComparator, mRuleWalker);
@@ -620,9 +633,10 @@ nsStyleSet::ProbePseudoStyleFor(nsIContent* aParentContent,
                "content (if non-null) must be element");
 
   if (aPseudoTag && presContext) {
-    if (mRuleProcessors[eAgentSheet].Count() ||
-        mRuleProcessors[eUserSheet].Count()  ||
-        mRuleProcessors[eDocSheet].Count()   ||
+    if (mRuleProcessors[eAgentSheet].Count()    ||
+        mRuleProcessors[eUserSheet].Count()     ||
+        mRuleProcessors[ePresHintSheet].Count() ||
+        mRuleProcessors[eDocSheet].Count()      ||
         mRuleProcessors[eOverrideSheet].Count()) {
       PseudoRulesMatchingData data(presContext, aParentContent, aPseudoTag,
                                    nsnull, mRuleWalker);
@@ -777,9 +791,10 @@ nsStyleSet::HasStateDependentStyle(nsIPresContext* aPresContext,
   nsReStyleHint result = nsReStyleHint(0);
 
   if (aContent->IsContentOfType(nsIContent::eELEMENT) &&
-      (mRuleProcessors[eAgentSheet].Count() ||
-       mRuleProcessors[eUserSheet].Count()  ||
-       mRuleProcessors[eDocSheet].Count()   ||
+      (mRuleProcessors[eAgentSheet].Count()    ||
+       mRuleProcessors[eUserSheet].Count()     ||
+       mRuleProcessors[ePresHintSheet].Count() ||
+       mRuleProcessors[eDocSheet].Count()      ||
        mRuleProcessors[eOverrideSheet].Count())) {  
     StatefulData data(aPresContext, aContent, aStateMask);
     WalkRuleProcessors(SheetHasStatefulStyle, &data);
@@ -820,9 +835,10 @@ nsStyleSet::HasAttributeDependentStyle(nsIPresContext* aPresContext,
   nsReStyleHint result = nsReStyleHint(0);
 
   if (aContent->IsContentOfType(nsIContent::eELEMENT) &&
-      (mRuleProcessors[eAgentSheet].Count() ||
-       mRuleProcessors[eUserSheet].Count()  ||
-       mRuleProcessors[eDocSheet].Count()   ||
+      (mRuleProcessors[eAgentSheet].Count()     ||
+       mRuleProcessors[eUserSheet].Count()      ||
+       mRuleProcessors[ePresHintSheet].Count()  ||
+       mRuleProcessors[eDocSheet].Count()       ||
        mRuleProcessors[eOverrideSheet].Count())) {  
     AttributeData data(aPresContext, aContent, aAttribute, aModType);
     WalkRuleProcessors(SheetHasAttributeStyle, &data);
diff --git a/mozilla/layout/style/nsStyleSet.h b/mozilla/layout/style/nsStyleSet.h
index e9c6f67ff3c..2548da5d535 100644
--- a/mozilla/layout/style/nsStyleSet.h
+++ b/mozilla/layout/style/nsStyleSet.h
@@ -155,6 +155,7 @@ class nsStyleSet
   enum sheetType {
     eAgentSheet,
     eUserSheet,
+    ePresHintSheet,
     eDocSheet,
     eOverrideSheet,
     eSheetTypeCount