diff --git a/mozilla/content/base/public/nsIStyleRuleProcessor.h b/mozilla/content/base/public/nsIStyleRuleProcessor.h
index c3e7cb4c1f4..78e612019b8 100644
--- a/mozilla/content/base/public/nsIStyleRuleProcessor.h
+++ b/mozilla/content/base/public/nsIStyleRuleProcessor.h
@@ -43,6 +43,7 @@
 #include "nsISupports.h"
 #include "nsIPresContext.h" // for nsCompatability
 #include "nsILinkHandler.h"
+#include "nsString.h"
 
 class nsISizeOfHandler;
 
@@ -78,6 +79,8 @@ struct RuleProcessorData {
     aContext->FreeToShell(sizeof(RuleProcessorData), this);
   };
 
+  const nsString* GetLang();
+
   nsIPresContext*   mPresContext;
   nsIContent*       mContent;
   nsIContent*       mParentContent; // if content, content->GetParent()
@@ -98,6 +101,10 @@ struct RuleProcessorData {
   PRInt32           mNameSpaceID;   // if content, content->GetNameSapce()
   RuleProcessorData* mPreviousSiblingData;
   RuleProcessorData* mParentData;
+
+protected:
+  nsAutoString mLanguage;
+  PRBool mIsLanguageValid;
 };
 
 struct ElementRuleProcessorData : public RuleProcessorData {
diff --git a/mozilla/content/base/src/nsStyleContext.cpp b/mozilla/content/base/src/nsStyleContext.cpp
index 3bc83916c92..bd760db159a 100644
--- a/mozilla/content/base/src/nsStyleContext.cpp
+++ b/mozilla/content/base/src/nsStyleContext.cpp
@@ -565,7 +565,7 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, PRInt32& aHint)
     
     // We begin by examining those style structs that are capable of causing the maximal
     // difference, a FRAMECHANGE.
-    // FRAMECHANGE Structs: Display, XUL, Content, UserInterface
+    // FRAMECHANGE Structs: Display, XUL, Content, UserInterface, Quotes
     if (aHint < maxHint) {
       const nsStyleDisplay* display = (const nsStyleDisplay*)PeekStyleData(eStyleStruct_Display);
       if (display) {
@@ -630,12 +630,26 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, PRInt32& aHint)
     }
 #endif
 
+    // If the quotes implementation is ever going to change we might not need
+    // a framechange here and a reflow should be sufficient.  See bug 35768.
+    if (aHint < maxHint) {
+      const nsStyleQuotes* quotes = (const nsStyleQuotes*)PeekStyleData(eStyleStruct_Quotes);
+      if (quotes) {
+        const nsStyleQuotes* otherQuotes = (const nsStyleQuotes*)aOther->GetStyleData(eStyleStruct_Quotes);
+        if (quotes != otherQuotes) {
+          hint = quotes->CalcDifference(*otherQuotes);
+          if (aHint < hint)
+            aHint = hint;
+        }
+      }
+    }
+
     // At this point, we know that the worst kind of damage we could do is a reflow.
     maxHint = NS_STYLE_HINT_REFLOW;
         
     // The following structs cause (as their maximal difference) a reflow to occur.
     // REFLOW Structs: Font, Margin, Padding, Border, List, Position, Text, TextReset,
-    // Visibility, Quotes, Table, TableBorder
+    // Visibility, Table, TableBorder
     if (aHint < maxHint) {
       const nsStyleFont* font = (const nsStyleFont*)PeekStyleData(eStyleStruct_Font);
       if (font) {
@@ -768,18 +782,6 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, PRInt32& aHint)
       }
     }
 
-    if (aHint < maxHint) {
-      const nsStyleQuotes* quotes = (const nsStyleQuotes*)PeekStyleData(eStyleStruct_Quotes);
-      if (quotes) {
-        const nsStyleQuotes* otherQuotes = (const nsStyleQuotes*)aOther->GetStyleData(eStyleStruct_Quotes);
-        if (quotes != otherQuotes) {
-          hint = quotes->CalcDifference(*otherQuotes);
-          if (aHint < hint)
-            aHint = hint;
-        }
-      }
-    }
-
     // At this point, we know that the worst kind of damage we could do is a re-render
     // (i.e., a VISUAL change).
     maxHint = NS_STYLE_HINT_VISUAL;
diff --git a/mozilla/content/html/style/src/nsCSSParser.cpp b/mozilla/content/html/style/src/nsCSSParser.cpp
index 29fcbddd7a7..5d6e80c7cd2 100644
--- a/mozilla/content/html/style/src/nsCSSParser.cpp
+++ b/mozilla/content/html/style/src/nsCSSParser.cpp
@@ -237,6 +237,8 @@ protected:
                          PRBool aIsNegated);
   void ParseNegatedSimpleSelector(PRInt32&  aDataMask, nsCSSSelector& aSelector,
                          PRInt32& aParsingStatus, PRInt32& aErrorCode);
+  void ParseLangSelector(nsCSSSelector& aSelector, PRInt32& aParsingStatus,
+                         PRInt32& aErrorCode);
 
   PRBool ParseSelectorList(PRInt32& aErrorCode, SelectorList*& aListHead);
   PRBool ParseSelectorGroup(PRInt32& aErrorCode, SelectorList*& aListHead);
@@ -1636,8 +1638,8 @@ PRBool CSSParserImpl::ParseSelectorGroup(PRInt32& aErrorCode,
     nsCSSSelector* listSel = list->mSelectors;
 
     // pull out pseudo elements here
-    nsAtomList* prevList = nsnull;
-    nsAtomList* pseudoClassList = listSel->mPseudoClassList;
+    nsAtomStringList* prevList = nsnull;
+    nsAtomStringList* pseudoClassList = listSel->mPseudoClassList;
     while (nsnull != pseudoClassList) {
       if (! IsPseudoClass(pseudoClassList->mAtom)) {
         havePseudoElement = PR_TRUE;
@@ -2201,7 +2203,7 @@ void CSSParserImpl::ParsePseudoSelector(PRInt32&  aDataMask,
   buffer.Append(PRUnichar(':'));
   buffer.Append(mToken.mIdent);
   ToLowerCase(buffer);
-  nsIAtom* pseudo = NS_NewAtom(buffer);
+  nsCOMPtr<nsIAtom> pseudo = do_GetAtom(buffer);
 
   if (eCSSToken_Ident != mToken.mType) {  // malformed selector
     if (eCSSToken_Function != mToken.mType ||
@@ -2211,19 +2213,17 @@ void CSSParserImpl::ParsePseudoSelector(PRInt32&  aDataMask,
           (!aIsNegated && IsTreePseudoElement(mToken.mIdent)) ||
 #endif
           // the negation pseudo-class is a function
-          (nsCSSAtoms::notPseudo == pseudo))) {
+          (nsCSSAtoms::notPseudo == pseudo) ||
+          // as is the lang pseudo-class
+          (nsCSSAtoms::langPseudo == pseudo))) {
       REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Expected identifier for pseudo-class selector not found"));
-      NS_RELEASE(pseudo);
       UngetToken();
       aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
       return;
-#ifdef INCLUDE_XUL
     }
-#endif
   }
 
   if (nsCSSAtoms::notPseudo == pseudo) {
-    NS_RELEASE(pseudo);
     if (aIsNegated) { // :not() can't be itself negated
       REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Negation pseudo-class can't be negated"));
       aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
@@ -2236,10 +2236,17 @@ void CSSParserImpl::ParsePseudoSelector(PRInt32&  aDataMask,
     }
   }    
   else if (IsPseudoClass(pseudo)) {
-    // XXX parse pseudo classes accepting arguments
     aDataMask |= SEL_MASK_PCLASS;
-    aSelector.AddPseudoClass(pseudo);
-    NS_RELEASE(pseudo);
+    if (nsCSSAtoms::langPseudo == pseudo) {
+      ParseLangSelector(aSelector, aParsingStatus, aErrorCode);
+    }
+    // XXX are there more pseudo classes which accept arguments ?
+    else {
+      aSelector.AddPseudoClass(pseudo);
+    }
+    if (SELECTOR_PARSING_ENDED_OK != aParsingStatus) {
+      return;
+    }
   }
   else {
     if (aIsNegated) { // pseudo-elements can't be negated
@@ -2250,7 +2257,6 @@ void CSSParserImpl::ParsePseudoSelector(PRInt32&  aDataMask,
     if (0 == (aDataMask & SEL_MASK_PELEM)) {
       aDataMask |= SEL_MASK_PELEM;
       aSelector.AddPseudoClass(pseudo); // store it here, it gets pulled later
-      NS_RELEASE(pseudo);
 
 #ifdef INCLUDE_XUL
       if (eCSSToken_Function == mToken.mType && 
@@ -2282,7 +2288,6 @@ void CSSParserImpl::ParsePseudoSelector(PRInt32&  aDataMask,
     else {  // multiple pseudo elements, not legal
       REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Extra pseudo-element"));
       UngetToken();
-      NS_RELEASE(pseudo);
       aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
       return;
     }
@@ -2360,6 +2365,43 @@ void CSSParserImpl::ParseNegatedSimpleSelector(PRInt32&  aDataMask,
   }
 }
 
+//
+// Parse the argument of a pseudo-class :lang()
+//
+void CSSParserImpl::ParseLangSelector(nsCSSSelector& aSelector,
+                                      PRInt32& aParsingStatus,
+                                      PRInt32& aErrorCode)
+{
+  // Check if we have the first parenthesis
+  if (ExpectSymbol(aErrorCode, '(', PR_FALSE)) {
+
+    if (! GetToken(aErrorCode, PR_TRUE)) { // premature eof
+      REPORT_UNEXPECTED_EOF(NS_LITERAL_STRING("argument to :lang selector"));
+      aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
+      return;
+    }
+    // We expect an identifier with a language abbreviation
+    if (eCSSToken_Ident != mToken.mType) {
+      REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Expected identifier for lang pseudo-class parameter"));
+      aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
+      return;
+    }
+
+    // Add the pseudo with the language parameter
+    aSelector.AddPseudoClass(nsCSSAtoms::langPseudo, mToken.mIdent.get());
+
+    // close the parenthesis
+    if (!ExpectSymbol(aErrorCode, ')', PR_TRUE)) {
+      REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Missing closing ')' in lang pseudo-class"));
+      aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
+    }
+  }
+  else {
+    REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Missing argument in lang pseudo-class"));
+    aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
+  }
+}
+
 /**
  * This is the format for selectors:
  * operator? [[namespace |]? element_name]? [ ID | class | attrib | pseudo ]*
diff --git a/mozilla/content/html/style/src/nsCSSStyleRule.cpp b/mozilla/content/html/style/src/nsCSSStyleRule.cpp
index 75e4a94ffae..dd826627550 100644
--- a/mozilla/content/html/style/src/nsCSSStyleRule.cpp
+++ b/mozilla/content/html/style/src/nsCSSStyleRule.cpp
@@ -69,6 +69,7 @@
 #include "nsINameSpace.h"
 #include "nsILookAndFeel.h"
 #include "nsRuleNode.h"
+#include "nsUnicharUtils.h"
 
 #include "nsIStyleSet.h"
 #include "nsISizeOfHandler.h"
@@ -117,7 +118,6 @@ nsAtomList::nsAtomList(nsIAtom* aAtom)
     mNext(nsnull)
 {
   MOZ_COUNT_CTOR(nsAtomList);
-  NS_IF_ADDREF(mAtom);
 }
 
 nsAtomList::nsAtomList(const nsString& aAtomValue)
@@ -125,7 +125,7 @@ nsAtomList::nsAtomList(const nsString& aAtomValue)
     mNext(nsnull)
 {
   MOZ_COUNT_CTOR(nsAtomList);
-  mAtom = NS_NewAtom(aAtomValue);
+  mAtom = do_GetAtom(aAtomValue);
 }
 
 nsAtomList::nsAtomList(const nsAtomList& aCopy)
@@ -133,14 +133,12 @@ nsAtomList::nsAtomList(const nsAtomList& aCopy)
     mNext(nsnull)
 {
   MOZ_COUNT_CTOR(nsAtomList);
-  NS_IF_ADDREF(mAtom);
   NS_IF_COPY(mNext, aCopy.mNext, nsAtomList);
 }
 
 nsAtomList::~nsAtomList(void)
 {
   MOZ_COUNT_DTOR(nsAtomList);
-  NS_IF_RELEASE(mAtom);
   NS_IF_DELETE(mNext);
 }
 
@@ -160,6 +158,63 @@ PRBool nsAtomList::Equals(const nsAtomList* aOther) const
   return PR_FALSE;
 }
 
+MOZ_DECL_CTOR_COUNTER(nsAtomStringList)
+
+nsAtomStringList::nsAtomStringList(nsIAtom* aAtom, const PRUnichar* aString)
+  : mAtom(aAtom),
+    mString(nsnull),
+    mNext(nsnull)
+{
+  MOZ_COUNT_CTOR(nsAtomStringList);
+  if (aString)
+    mString = nsCRT::strdup(aString);
+}
+
+nsAtomStringList::nsAtomStringList(const nsString& aAtomValue,
+                                   const PRUnichar* aString)
+  : mAtom(nsnull),
+    mString(nsnull),
+    mNext(nsnull)
+{
+  MOZ_COUNT_CTOR(nsAtomStringList);
+  mAtom = do_GetAtom(aAtomValue);
+  if (aString)
+    mString = nsCRT::strdup(aString);
+}
+
+nsAtomStringList::nsAtomStringList(const nsAtomStringList& aCopy)
+  : mAtom(aCopy.mAtom),
+    mString(nsnull),
+    mNext(nsnull)
+{
+  MOZ_COUNT_CTOR(nsAtomStringList);
+  if (aCopy.mString)
+    mString = nsCRT::strdup(aCopy.mString);
+  NS_IF_COPY(mNext, aCopy.mNext, nsAtomStringList);
+}
+
+nsAtomStringList::~nsAtomStringList(void)
+{
+  MOZ_COUNT_DTOR(nsAtomStringList);
+  if (mString)
+    nsCRT::free(mString);
+  NS_IF_DELETE(mNext);
+}
+
+PRBool nsAtomStringList::Equals(const nsAtomStringList* aOther) const
+{
+  return (this == aOther) ||
+         (aOther &&
+          mAtom == aOther->mAtom &&
+          !mString == !aOther->mString &&
+          !mNext == !aOther->mNext &&
+          (!mNext || mNext->Equals(aOther->mNext)) &&
+          // Check strings last, since it's the slowest check.
+          (!mString || nsDependentString(mString).Equals(
+                                        nsDependentString(aOther->mString),
+                                        nsCaseInsensitiveStringComparator())));
+}
+
 MOZ_DECL_CTOR_COUNTER(nsAttrSelector)
 
 #ifdef DEBUG_REFS
@@ -336,10 +391,9 @@ nsCSSSelector::nsCSSSelector(const nsCSSSelector& aCopy)
     mNext(nsnull)
 {
   MOZ_COUNT_CTOR(nsCSSSelector);
-  NS_IF_ADDREF(mTag);
   NS_IF_COPY(mIDList, aCopy.mIDList, nsAtomList);
   NS_IF_COPY(mClassList, aCopy.mClassList, nsAtomList);
-  NS_IF_COPY(mPseudoClassList, aCopy.mPseudoClassList, nsAtomList);
+  NS_IF_COPY(mPseudoClassList, aCopy.mPseudoClassList, nsAtomStringList);
   NS_IF_COPY(mAttrList, aCopy.mAttrList, nsAttrSelector);
   NS_IF_COPY(mNegations, aCopy.mNegations, nsCSSSelector);
   
@@ -362,7 +416,6 @@ nsCSSSelector::~nsCSSSelector(void)
 
 nsCSSSelector& nsCSSSelector::operator=(const nsCSSSelector& aCopy)
 {
-  NS_IF_RELEASE(mTag);
   NS_IF_DELETE(mIDList);
   NS_IF_DELETE(mClassList);
   NS_IF_DELETE(mPseudoClassList);
@@ -373,12 +426,11 @@ nsCSSSelector& nsCSSSelector::operator=(const nsCSSSelector& aCopy)
   mTag          = aCopy.mTag;
   NS_IF_COPY(mIDList, aCopy.mIDList, nsAtomList);
   NS_IF_COPY(mClassList, aCopy.mClassList, nsAtomList);
-  NS_IF_COPY(mPseudoClassList, aCopy.mPseudoClassList, nsAtomList);
+  NS_IF_COPY(mPseudoClassList, aCopy.mPseudoClassList, nsAtomStringList);
   NS_IF_COPY(mAttrList, aCopy.mAttrList, nsAttrSelector);
   mOperator     = aCopy.mOperator;
   NS_IF_COPY(mNegations, aCopy.mNegations, nsCSSSelector);
 
-  NS_IF_ADDREF(mTag);
   return *this;
 }
 
@@ -446,7 +498,7 @@ PRBool nsCSSSelector::Equals(const nsCSSSelector* aOther) const
 void nsCSSSelector::Reset(void)
 {
   mNameSpace = kNameSpaceID_Unknown;
-  NS_IF_RELEASE(mTag);
+  mTag = nsnull;
   NS_IF_DELETE(mIDList);
   NS_IF_DELETE(mClassList);
   NS_IF_DELETE(mPseudoClassList);
@@ -462,10 +514,10 @@ void nsCSSSelector::SetNameSpace(PRInt32 aNameSpace)
 
 void nsCSSSelector::SetTag(const nsString& aTag)
 {
-  NS_IF_RELEASE(mTag);
-  if (!aTag.IsEmpty()) {
-    mTag = NS_NewAtom(aTag);
-  }
+  if (aTag.IsEmpty())
+    mTag = nsnull;
+  else
+    mTag = do_GetAtom(aTag);
 }
 
 void nsCSSSelector::AddID(const nsString& aID)
@@ -490,25 +542,27 @@ void nsCSSSelector::AddClass(const nsString& aClass)
   }
 }
 
-void nsCSSSelector::AddPseudoClass(const nsString& aPseudoClass)
+void nsCSSSelector::AddPseudoClass(const nsString& aPseudoClass,
+                                   const PRUnichar* aString)
 {
   if (!aPseudoClass.IsEmpty()) {
-    nsAtomList** list = &mPseudoClassList;
+    nsAtomStringList** list = &mPseudoClassList;
     while (nsnull != *list) {
       list = &((*list)->mNext);
     }
-    *list = new nsAtomList(aPseudoClass);
+    *list = new nsAtomStringList(aPseudoClass, aString);
   }
 }
 
-void nsCSSSelector::AddPseudoClass(nsIAtom* aPseudoClass)
+void nsCSSSelector::AddPseudoClass(nsIAtom* aPseudoClass,
+                                   const PRUnichar* aString)
 {
   if (nsnull != aPseudoClass) {
-    nsAtomList** list = &mPseudoClassList;
+    nsAtomStringList** list = &mPseudoClassList;
     while (nsnull != *list) {
       list = &((*list)->mNext);
     }
-    *list = new nsAtomList(aPseudoClass);
+    *list = new nsAtomStringList(aPseudoClass, aString);
   }
 }
 
@@ -557,10 +611,10 @@ PRInt32 nsCSSSelector::CalcWeight(void) const
     weight += 0x000100;
     list = list->mNext;
   }
-  list = mPseudoClassList;
-  while (nsnull != list) {
+  nsAtomStringList *plist = mPseudoClassList;
+  while (nsnull != plist) {
     weight += 0x000100;
-    list = list->mNext;
+    plist = plist->mNext;
   }
   nsAttrSelector* attr = mAttrList;
   while (nsnull != attr) {
@@ -647,7 +701,7 @@ void nsCSSSelector::SizeOf(nsISizeOfHandler *aSizeOfHandler, PRUint32 &aSize)
     }
   }
   if(mPseudoClassList && uniqueItems->AddItem(mPseudoClassList)){
-    nsAtomList *pNext = nsnull;
+    nsAtomStringList *pNext = nsnull;
     pNext = mPseudoClassList;    
     while(pNext){
       if(pNext->mAtom && uniqueItems->AddItem(pNext->mAtom)){
@@ -832,11 +886,16 @@ nsresult nsCSSSelector::ToString( nsAString& aString, nsICSSStyleSheet* aSheet,
 
   // Append each pseudo-class in the linked list
   if (mPseudoClassList) {
-    nsAtomList* list = mPseudoClassList;
+    nsAtomStringList* list = mPseudoClassList;
     while (list != nsnull) {
       list->mAtom->GetUnicode(&temp);
       NS_IF_NEGATED_START(aIsNegated, aString)
       aString.Append(temp);
+      if (nsnull != list->mString) {
+        aString.Append(PRUnichar('('));
+        aString.Append(list->mString);
+        aString.Append(PRUnichar(')'));
+      }
       NS_IF_NEGATED_END(aIsNegated, aString)
       list = list->mNext;
     }
diff --git a/mozilla/content/html/style/src/nsCSSStyleSheet.cpp b/mozilla/content/html/style/src/nsCSSStyleSheet.cpp
index a7ecbb6e5a8..5785d7af8c1 100644
--- a/mozilla/content/html/style/src/nsCSSStyleSheet.cpp
+++ b/mozilla/content/html/style/src/nsCSSStyleSheet.cpp
@@ -245,7 +245,7 @@ RuleHash_CIMatchEntry(PLDHashTable *table, const PLDHashEntryHdr *hdr,
   nsIAtom *entry_atom = NS_CONST_CAST(nsIAtom*, NS_STATIC_CAST(const nsIAtom*,
              table->ops->getKey(table, NS_CONST_CAST(PLDHashEntryHdr*, hdr))));
 
-  // Check for case-insensitive match first.
+  // Check for case-sensitive match first.
   if (match_atom == entry_atom)
     return PR_TRUE;
 
@@ -2065,7 +2065,7 @@ CSSStyleSheetImpl::ClearMedia(void)
 NS_IMETHODIMP
 CSSStyleSheetImpl::GetEnabled(PRBool& aEnabled) const
 {
-  aEnabled = ((PR_TRUE == mDisabled) ? PR_FALSE : PR_TRUE);
+  aEnabled = !mDisabled;
   return NS_OK;
 }
 
@@ -2073,7 +2073,7 @@ NS_IMETHODIMP
 CSSStyleSheetImpl::SetEnabled(PRBool aEnabled)
 {
   PRBool oldState = mDisabled;
-  mDisabled = ((PR_TRUE == aEnabled) ? PR_FALSE : PR_TRUE);
+  mDisabled = !aEnabled;
 
   if ((nsnull != mDocument) && (mDisabled != oldState)) {
     mDocument->SetStyleSheetDisabledState(this, mDisabled);
@@ -2353,6 +2353,16 @@ CSSStyleSheetImpl::CheckRuleForAttributes(nsICSSRule *aRule)
           DependentAtomKey key(sel->mAttr);
           mInner->mRelevantAttributes.Put(&key, sel->mAttr);
         }
+
+        // Search for the :lang() pseudo class.  If it is there add
+        // the lang attribute to the relevant attribute list.
+        for (nsAtomStringList* p = iter->mPseudoClassList; p; p = p->mNext) {
+          if (p->mAtom == nsCSSAtoms::langPseudo) {
+            DependentAtomKey langKey(nsHTMLAtoms::lang);
+            mInner->mRelevantAttributes.Put(&langKey, nsHTMLAtoms::lang);
+            break;
+          }
+        }
       }
     } /* fall-through */
     default:
@@ -3373,6 +3383,7 @@ RuleProcessorData::RuleProcessorData(nsIPresContext* aPresContext,
   mNameSpaceID = kNameSpaceID_Unknown;
   mPreviousSiblingData = nsnull;
   mParentData = nsnull;
+  mIsLanguageValid = PR_FALSE;
 
   // get the compat. mode (unless it is provided)
   if(!aCompat) {
@@ -3418,7 +3429,7 @@ RuleProcessorData::RuleProcessorData(nsIPresContext* aPresContext,
 
     // if HTML content and it has some attributes, check for an HTML link
     // NOTE: optimization: cannot be a link if no attributes (since it needs an href)
-    if (PR_TRUE == mIsHTMLContent && mHasAttributes) {
+    if (mIsHTMLContent && mHasAttributes) {
       // check if it is an HTML Link
       if(nsStyleUtil::IsHTMLLink(aContent, mContentTag, mPresContext, &mLinkState)) {
         mIsHTMLLink = PR_TRUE;
@@ -3427,9 +3438,9 @@ RuleProcessorData::RuleProcessorData(nsIPresContext* aPresContext,
 
     // if not an HTML link, check for a simple xlink (cannot be both HTML link and xlink)
     // NOTE: optimization: cannot be an XLink if no attributes (since it needs an 
-    if(PR_FALSE == mIsHTMLLink &&
+    if(!mIsHTMLLink &&
        mHasAttributes && 
-       !(aContent->IsContentOfType(nsIContent::eHTML) || aContent->IsContentOfType(nsIContent::eXUL)) && 
+       !(mIsHTMLContent || aContent->IsContentOfType(nsIContent::eXUL)) && 
        nsStyleUtil::IsSimpleXlink(aContent, mPresContext, &mLinkState)) {
       mIsSimpleXLink = PR_TRUE;
     } 
@@ -3463,6 +3474,39 @@ RuleProcessorData::~RuleProcessorData()
   NS_IF_RELEASE(mStyledContent);
 }
 
+const nsString* RuleProcessorData::GetLang(void)
+{
+  if (!mIsLanguageValid) {
+    mIsLanguageValid = PR_TRUE;
+    mLanguage.SetLength(0);
+    nsCOMPtr<nsIContent> content = mContent;
+    while (content) {
+      PRInt32 attrCount = 0;
+      content->GetAttrCount(attrCount);
+      if (attrCount > 0) {
+        // xml:lang has precedence over lang on HTML elements (see
+        // XHTML1 section C.7).
+        nsAutoString value;
+        nsresult attrState = content->GetAttr(kNameSpaceID_XML,
+                                              nsHTMLAtoms::lang, value);
+        if (attrState != NS_CONTENT_ATTR_HAS_VALUE &&
+            content->IsContentOfType(nsIContent::eHTML)) {
+          attrState = content->GetAttr(kNameSpaceID_None,
+                                       nsHTMLAtoms::lang, value);
+        }
+        if (attrState == NS_CONTENT_ATTR_HAS_VALUE) {
+          mLanguage = value;
+          break;
+        }
+      }
+      nsIContent *parent;
+      content->GetParent(parent);
+      content = dont_AddRef(parent);
+    }
+  }
+  return &mLanguage;
+}
+
 static const PRUnichar kNullCh = PRUnichar('\0');
 
 static PRBool ValueIncludes(const nsString& aValueList, const nsString& aValue, PRBool aCaseSensitive)
@@ -3564,6 +3608,39 @@ static PRBool IsSignificantChild(nsIContent* aChild, PRBool aAcceptNonWhitespace
   return PR_FALSE;
 }
 
+static PRBool
+DashMatchCompare(const nsAString& aAttributeValue,
+                 const nsAString& aSelectorValue,
+                 const PRBool aCaseSensitive)
+{
+  PRBool result;
+  PRUint32 selectorLen = aSelectorValue.Length();
+  PRUint32 attributeLen = aAttributeValue.Length();
+  if (selectorLen > attributeLen) {
+    result = PR_FALSE;
+  }
+  else {
+    nsAString::const_iterator iter;
+    if (selectorLen != attributeLen &&
+        *aAttributeValue.BeginReading(iter).advance(selectorLen) !=
+            PRUnichar('-')) {
+      // to match, the aAttributeValue must have a dash after the end of
+      // the aSelectorValue's text (unless the aSelectorValue and the
+      // aAttributeValue have the same text)
+      result = PR_FALSE;
+    }
+    else {
+      const nsAString& attributeSubstring =
+        Substring(aAttributeValue, 0, selectorLen);
+      if (aCaseSensitive)
+        result = attributeSubstring.Equals(aSelectorValue);
+      else
+        result = attributeSubstring.Equals(aSelectorValue,
+                                          nsCaseInsensitiveStringComparator());
+    }
+  }
+  return result;
+}
 
 // NOTE:  The |aStateMask| code isn't going to work correctly anymore if
 // we start batching style changes, because if multiple states change in
@@ -3606,7 +3683,7 @@ static PRBool SelectorMatches(RuleProcessorData &data,
   if (nsnull != aSelector->mPseudoClassList) {  // test for pseudo class match
     // first-child, root, lang, active, focus, hover, link, visited...
     // XXX disabled, enabled, selected, selection
-    nsAtomList* pseudoClass = aSelector->mPseudoClassList;
+    nsAtomStringList* pseudoClass = aSelector->mPseudoClassList;
 
     while (result && (nsnull != pseudoClass)) {
       if ((nsCSSAtoms::firstChildPseudo == pseudoClass->mAtom) ||
@@ -3686,8 +3763,49 @@ static PRBool SelectorMatches(RuleProcessorData &data,
                    ? localTrue : localFalse;
       }
       else if (nsCSSAtoms::langPseudo == pseudoClass->mAtom) {
-        // XXX not yet implemented
-        result = PR_FALSE;
+        NS_ASSERTION(nsnull != pseudoClass->mString, "null lang parameter");
+        result = localFalse;
+        if (pseudoClass->mString && *pseudoClass->mString) {
+          // We have to determine the language of the current element.  Since
+          // this is currently no property and since the language is inherited
+          // from the parent we have to be prepared to look at all parent
+          // nodes.  The language itself is encoded in the LANG attribute.
+          const nsString* lang = data.GetLang();
+          if (!lang->IsEmpty()) {
+            result = localTrue == DashMatchCompare(*lang,
+                            nsDependentString(pseudoClass->mString), PR_FALSE);
+          }
+          else {
+            nsCOMPtr<nsIDocument> doc;
+            data.mContent->GetDocument(*getter_AddRefs(doc));
+            if (doc) {
+              // Try to get the language from the HTTP header or if this
+              // is missing as well from the preferences.
+              // The content language can be a comma-separated list of
+              // language codes.
+              nsAutoString language;
+              if (NS_SUCCEEDED(doc->GetContentLanguage(language))) {
+                nsDependentString langString(pseudoClass->mString);
+                language.StripWhitespace();
+                PRInt32 begin = 0;
+                PRInt32 len = language.Length();
+                while (begin < len) {
+                  PRInt32 end = language.FindChar(PRUnichar(','), begin);
+                  if (end == kNotFound) {
+                    end = len;
+                  }
+                  if (DashMatchCompare(Substring(language, begin, end-begin),
+                                       langString,
+                                       PR_FALSE)) {
+                    result = localTrue;
+                    break;
+                  }
+                  begin = end + 1;
+                }
+              }
+            }
+          }
+        }
       }
       else if (IsEventPseudo(pseudoClass->mAtom)) {
         // check if the element is event-sensitive
@@ -3783,36 +3901,17 @@ static PRBool SelectorMatches(RuleProcessorData &data,
           switch (attr->mFunction) {
             case NS_ATTR_FUNC_EQUALS: 
               if (isCaseSensitive) {
-                result = PRBool(localTrue == value.Equals(attr->mValue));
+                result = localTrue == value.Equals(attr->mValue);
               }
               else {
-                result = PRBool(localTrue == value.Equals(attr->mValue, nsCaseInsensitiveStringComparator()));
+                result = localTrue == value.Equals(attr->mValue, nsCaseInsensitiveStringComparator());
               }
               break;
             case NS_ATTR_FUNC_INCLUDES: 
-              result = PRBool(localTrue == ValueIncludes(value, attr->mValue, isCaseSensitive));
+              result = localTrue == ValueIncludes(value, attr->mValue, isCaseSensitive);
               break;
             case NS_ATTR_FUNC_DASHMATCH: 
-              {
-                PRUint32 selLen = attr->mValue.Length();
-                PRUint32 valLen = value.Length();
-                if (selLen > valLen) {
-                  result = localFalse;
-                } else {
-                  if (selLen != valLen &&
-                      value.CharAt(selLen) != PRUnichar('-')) {
-                    // to match, the value must have a dash after the end of
-                    // the selector's text (unless the selector and the value
-                    // have the same text)
-                    result = localFalse;
-                    break;
-                  }
-                  if (isCaseSensitive)
-                    result = PRBool(localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsDefaultStringComparator()));
-                  else
-                    result = PRBool(localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsCaseInsensitiveStringComparator()));
-                }
-              }
+              result = localTrue == DashMatchCompare(value, attr->mValue, isCaseSensitive);
               break;
             case NS_ATTR_FUNC_ENDSMATCH:
               {
@@ -3822,9 +3921,9 @@ static PRBool SelectorMatches(RuleProcessorData &data,
                   result = localFalse;
                 } else {
                   if (isCaseSensitive)
-                    result = PRBool(localTrue == Substring(value, valLen - selLen, selLen).Equals(attr->mValue, nsDefaultStringComparator()));
+                    result = localTrue == Substring(value, valLen - selLen, selLen).Equals(attr->mValue, nsDefaultStringComparator());
                   else
-                    result = PRBool(localTrue == Substring(value, valLen - selLen, selLen).Equals(attr->mValue, nsCaseInsensitiveStringComparator()));
+                    result = localTrue == Substring(value, valLen - selLen, selLen).Equals(attr->mValue, nsCaseInsensitiveStringComparator());
                 }
               }
               break;
@@ -3836,14 +3935,14 @@ static PRBool SelectorMatches(RuleProcessorData &data,
                   result = localFalse;
                 } else {
                   if (isCaseSensitive)
-                    result = PRBool(localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsDefaultStringComparator()));
+                    result = localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsDefaultStringComparator());
                   else
-                    result = PRBool(localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsCaseInsensitiveStringComparator()));
+                    result = localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsCaseInsensitiveStringComparator());
                 }
               }
               break;
             case NS_ATTR_FUNC_CONTAINSMATCH:
-              result = PRBool(localTrue == (FindInReadable(attr->mValue, value, nsCaseInsensitiveStringComparator())));
+              result = localTrue == (FindInReadable(attr->mValue, value, nsCaseInsensitiveStringComparator()));
               break;
           }
         }
@@ -4210,6 +4309,7 @@ PRBool WeightedRulesSizeEnumFunc( nsISupports *aRule, void *aData )
 {
   nsICSSStyleRule* rule = (nsICSSStyleRule*)aRule;
   CascadeSizeEnumData *pData = (CascadeSizeEnumData *)aData;
+
   NS_ASSERTION(rule && pData, "null arguments not supported");
 
   if(! pData->uniqueItems->AddItem((void*)rule)){
@@ -4335,7 +4435,7 @@ CSSRuleProcessor::ClearRuleCascades(void)
 inline
 PRBool IsStateSelector(nsCSSSelector& aSelector)
 {
-  nsAtomList* pseudoClass = aSelector.mPseudoClassList;
+  nsAtomStringList* pseudoClass = aSelector.mPseudoClassList;
   while (pseudoClass) {
     if ((pseudoClass->mAtom == nsCSSAtoms::activePseudo) ||
         (pseudoClass->mAtom == nsCSSAtoms::checkedPseudo) ||
diff --git a/mozilla/content/html/style/src/nsICSSStyleRule.h b/mozilla/content/html/style/src/nsICSSStyleRule.h
index 7d9e4e1b93f..f19ed554166 100644
--- a/mozilla/content/html/style/src/nsICSSStyleRule.h
+++ b/mozilla/content/html/style/src/nsICSSStyleRule.h
@@ -42,8 +42,10 @@
 //#include <stdio.h>
 #include "nsICSSRule.h"
 #include "nsString.h"
+#include "nsCOMPtr.h"
 #include "nsCSSProps.h"
 #include "nsCSSValue.h"
+#include "nsIAtom.h"
 
 class nsISizeOfHandler;
 
@@ -60,8 +62,21 @@ public:
   ~nsAtomList(void);
   PRBool Equals(const nsAtomList* aOther) const;
 
-  nsIAtom*    mAtom;
-  nsAtomList* mNext;
+  nsCOMPtr<nsIAtom> mAtom;
+  nsAtomList*       mNext;
+};
+
+struct nsAtomStringList {
+public:
+  nsAtomStringList(nsIAtom* aAtom, const PRUnichar *aString = nsnull);
+  nsAtomStringList(const nsString& aAtomValue, const PRUnichar *aString = nsnull);
+  nsAtomStringList(const nsAtomStringList& aCopy);
+  ~nsAtomStringList(void);
+  PRBool Equals(const nsAtomStringList* aOther) const;
+
+  nsCOMPtr<nsIAtom> mAtom;
+  PRUnichar*        mString;
+  nsAtomStringList* mNext;
 };
 
 #define NS_ATTR_FUNC_SET        0     // [attr]
@@ -112,8 +127,8 @@ public:
   void SetTag(const nsString& aTag);
   void AddID(const nsString& aID);
   void AddClass(const nsString& aClass);
-  void AddPseudoClass(const nsString& aPseudoClass);
-  void AddPseudoClass(nsIAtom* aPseudoClass);
+  void AddPseudoClass(const nsString& aPseudoClass, const PRUnichar* aString = nsnull);
+  void AddPseudoClass(nsIAtom* aPseudoClass, const PRUnichar* aString = nsnull);
   void AddAttribute(PRInt32 aNameSpace, const nsString& aAttr);
   void AddAttribute(PRInt32 aNameSpace, const nsString& aAttr, PRUint8 aFunc, 
                     const nsString& aValue, PRBool aCaseSensitive);
@@ -133,10 +148,11 @@ private:
 
 public:
   PRInt32         mNameSpace;
-  nsIAtom*        mTag;
+  nsCOMPtr<nsIAtom> mTag;
   nsAtomList*     mIDList;
   nsAtomList*     mClassList;
-  nsAtomList*     mPseudoClassList;
+  nsAtomStringList* mPseudoClassList; // atom for the pseudo, string for
+                                      // the argument to functional pseudos
   nsAttrSelector* mAttrList;
   PRUnichar       mOperator;
   nsCSSSelector*  mNegations;
diff --git a/mozilla/content/shared/src/nsStyleStruct.cpp b/mozilla/content/shared/src/nsStyleStruct.cpp
index f8ca3208f5d..c9660ee1377 100644
--- a/mozilla/content/shared/src/nsStyleStruct.cpp
+++ b/mozilla/content/shared/src/nsStyleStruct.cpp
@@ -1246,17 +1246,19 @@ nsStyleQuotes::nsStyleQuotes(const nsStyleQuotes& aSource)
 PRInt32 
 nsStyleQuotes::CalcDifference(const nsStyleQuotes& aOther) const
 {
+  // If the quotes implementation is ever going to change we might not need
+  // a framechange here and a reflow should be sufficient.  See bug 35768.
   if (mQuotesCount == aOther.mQuotesCount) {
     PRUint32 ix = (mQuotesCount * 2);
     while (0 < ix--) {
       if (mQuotes[ix] != aOther.mQuotes[ix]) {
-        return NS_STYLE_HINT_REFLOW;
+        return NS_STYLE_HINT_FRAMECHANGE;
       }
     }
 
     return NS_STYLE_HINT_NONE;
   }
-  return NS_STYLE_HINT_REFLOW;
+  return NS_STYLE_HINT_FRAMECHANGE;
 }
 
 // --------------------
diff --git a/mozilla/layout/style/nsCSSParser.cpp b/mozilla/layout/style/nsCSSParser.cpp
index 29fcbddd7a7..5d6e80c7cd2 100644
--- a/mozilla/layout/style/nsCSSParser.cpp
+++ b/mozilla/layout/style/nsCSSParser.cpp
@@ -237,6 +237,8 @@ protected:
                          PRBool aIsNegated);
   void ParseNegatedSimpleSelector(PRInt32&  aDataMask, nsCSSSelector& aSelector,
                          PRInt32& aParsingStatus, PRInt32& aErrorCode);
+  void ParseLangSelector(nsCSSSelector& aSelector, PRInt32& aParsingStatus,
+                         PRInt32& aErrorCode);
 
   PRBool ParseSelectorList(PRInt32& aErrorCode, SelectorList*& aListHead);
   PRBool ParseSelectorGroup(PRInt32& aErrorCode, SelectorList*& aListHead);
@@ -1636,8 +1638,8 @@ PRBool CSSParserImpl::ParseSelectorGroup(PRInt32& aErrorCode,
     nsCSSSelector* listSel = list->mSelectors;
 
     // pull out pseudo elements here
-    nsAtomList* prevList = nsnull;
-    nsAtomList* pseudoClassList = listSel->mPseudoClassList;
+    nsAtomStringList* prevList = nsnull;
+    nsAtomStringList* pseudoClassList = listSel->mPseudoClassList;
     while (nsnull != pseudoClassList) {
       if (! IsPseudoClass(pseudoClassList->mAtom)) {
         havePseudoElement = PR_TRUE;
@@ -2201,7 +2203,7 @@ void CSSParserImpl::ParsePseudoSelector(PRInt32&  aDataMask,
   buffer.Append(PRUnichar(':'));
   buffer.Append(mToken.mIdent);
   ToLowerCase(buffer);
-  nsIAtom* pseudo = NS_NewAtom(buffer);
+  nsCOMPtr<nsIAtom> pseudo = do_GetAtom(buffer);
 
   if (eCSSToken_Ident != mToken.mType) {  // malformed selector
     if (eCSSToken_Function != mToken.mType ||
@@ -2211,19 +2213,17 @@ void CSSParserImpl::ParsePseudoSelector(PRInt32&  aDataMask,
           (!aIsNegated && IsTreePseudoElement(mToken.mIdent)) ||
 #endif
           // the negation pseudo-class is a function
-          (nsCSSAtoms::notPseudo == pseudo))) {
+          (nsCSSAtoms::notPseudo == pseudo) ||
+          // as is the lang pseudo-class
+          (nsCSSAtoms::langPseudo == pseudo))) {
       REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Expected identifier for pseudo-class selector not found"));
-      NS_RELEASE(pseudo);
       UngetToken();
       aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
       return;
-#ifdef INCLUDE_XUL
     }
-#endif
   }
 
   if (nsCSSAtoms::notPseudo == pseudo) {
-    NS_RELEASE(pseudo);
     if (aIsNegated) { // :not() can't be itself negated
       REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Negation pseudo-class can't be negated"));
       aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
@@ -2236,10 +2236,17 @@ void CSSParserImpl::ParsePseudoSelector(PRInt32&  aDataMask,
     }
   }    
   else if (IsPseudoClass(pseudo)) {
-    // XXX parse pseudo classes accepting arguments
     aDataMask |= SEL_MASK_PCLASS;
-    aSelector.AddPseudoClass(pseudo);
-    NS_RELEASE(pseudo);
+    if (nsCSSAtoms::langPseudo == pseudo) {
+      ParseLangSelector(aSelector, aParsingStatus, aErrorCode);
+    }
+    // XXX are there more pseudo classes which accept arguments ?
+    else {
+      aSelector.AddPseudoClass(pseudo);
+    }
+    if (SELECTOR_PARSING_ENDED_OK != aParsingStatus) {
+      return;
+    }
   }
   else {
     if (aIsNegated) { // pseudo-elements can't be negated
@@ -2250,7 +2257,6 @@ void CSSParserImpl::ParsePseudoSelector(PRInt32&  aDataMask,
     if (0 == (aDataMask & SEL_MASK_PELEM)) {
       aDataMask |= SEL_MASK_PELEM;
       aSelector.AddPseudoClass(pseudo); // store it here, it gets pulled later
-      NS_RELEASE(pseudo);
 
 #ifdef INCLUDE_XUL
       if (eCSSToken_Function == mToken.mType && 
@@ -2282,7 +2288,6 @@ void CSSParserImpl::ParsePseudoSelector(PRInt32&  aDataMask,
     else {  // multiple pseudo elements, not legal
       REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Extra pseudo-element"));
       UngetToken();
-      NS_RELEASE(pseudo);
       aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
       return;
     }
@@ -2360,6 +2365,43 @@ void CSSParserImpl::ParseNegatedSimpleSelector(PRInt32&  aDataMask,
   }
 }
 
+//
+// Parse the argument of a pseudo-class :lang()
+//
+void CSSParserImpl::ParseLangSelector(nsCSSSelector& aSelector,
+                                      PRInt32& aParsingStatus,
+                                      PRInt32& aErrorCode)
+{
+  // Check if we have the first parenthesis
+  if (ExpectSymbol(aErrorCode, '(', PR_FALSE)) {
+
+    if (! GetToken(aErrorCode, PR_TRUE)) { // premature eof
+      REPORT_UNEXPECTED_EOF(NS_LITERAL_STRING("argument to :lang selector"));
+      aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
+      return;
+    }
+    // We expect an identifier with a language abbreviation
+    if (eCSSToken_Ident != mToken.mType) {
+      REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Expected identifier for lang pseudo-class parameter"));
+      aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
+      return;
+    }
+
+    // Add the pseudo with the language parameter
+    aSelector.AddPseudoClass(nsCSSAtoms::langPseudo, mToken.mIdent.get());
+
+    // close the parenthesis
+    if (!ExpectSymbol(aErrorCode, ')', PR_TRUE)) {
+      REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Missing closing ')' in lang pseudo-class"));
+      aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
+    }
+  }
+  else {
+    REPORT_UNEXPECTED_TOKEN(NS_LITERAL_STRING("Missing argument in lang pseudo-class"));
+    aParsingStatus = SELECTOR_PARSING_STOPPED_ERROR;
+  }
+}
+
 /**
  * This is the format for selectors:
  * operator? [[namespace |]? element_name]? [ ID | class | attrib | pseudo ]*
diff --git a/mozilla/layout/style/nsCSSStyleRule.cpp b/mozilla/layout/style/nsCSSStyleRule.cpp
index 75e4a94ffae..dd826627550 100644
--- a/mozilla/layout/style/nsCSSStyleRule.cpp
+++ b/mozilla/layout/style/nsCSSStyleRule.cpp
@@ -69,6 +69,7 @@
 #include "nsINameSpace.h"
 #include "nsILookAndFeel.h"
 #include "nsRuleNode.h"
+#include "nsUnicharUtils.h"
 
 #include "nsIStyleSet.h"
 #include "nsISizeOfHandler.h"
@@ -117,7 +118,6 @@ nsAtomList::nsAtomList(nsIAtom* aAtom)
     mNext(nsnull)
 {
   MOZ_COUNT_CTOR(nsAtomList);
-  NS_IF_ADDREF(mAtom);
 }
 
 nsAtomList::nsAtomList(const nsString& aAtomValue)
@@ -125,7 +125,7 @@ nsAtomList::nsAtomList(const nsString& aAtomValue)
     mNext(nsnull)
 {
   MOZ_COUNT_CTOR(nsAtomList);
-  mAtom = NS_NewAtom(aAtomValue);
+  mAtom = do_GetAtom(aAtomValue);
 }
 
 nsAtomList::nsAtomList(const nsAtomList& aCopy)
@@ -133,14 +133,12 @@ nsAtomList::nsAtomList(const nsAtomList& aCopy)
     mNext(nsnull)
 {
   MOZ_COUNT_CTOR(nsAtomList);
-  NS_IF_ADDREF(mAtom);
   NS_IF_COPY(mNext, aCopy.mNext, nsAtomList);
 }
 
 nsAtomList::~nsAtomList(void)
 {
   MOZ_COUNT_DTOR(nsAtomList);
-  NS_IF_RELEASE(mAtom);
   NS_IF_DELETE(mNext);
 }
 
@@ -160,6 +158,63 @@ PRBool nsAtomList::Equals(const nsAtomList* aOther) const
   return PR_FALSE;
 }
 
+MOZ_DECL_CTOR_COUNTER(nsAtomStringList)
+
+nsAtomStringList::nsAtomStringList(nsIAtom* aAtom, const PRUnichar* aString)
+  : mAtom(aAtom),
+    mString(nsnull),
+    mNext(nsnull)
+{
+  MOZ_COUNT_CTOR(nsAtomStringList);
+  if (aString)
+    mString = nsCRT::strdup(aString);
+}
+
+nsAtomStringList::nsAtomStringList(const nsString& aAtomValue,
+                                   const PRUnichar* aString)
+  : mAtom(nsnull),
+    mString(nsnull),
+    mNext(nsnull)
+{
+  MOZ_COUNT_CTOR(nsAtomStringList);
+  mAtom = do_GetAtom(aAtomValue);
+  if (aString)
+    mString = nsCRT::strdup(aString);
+}
+
+nsAtomStringList::nsAtomStringList(const nsAtomStringList& aCopy)
+  : mAtom(aCopy.mAtom),
+    mString(nsnull),
+    mNext(nsnull)
+{
+  MOZ_COUNT_CTOR(nsAtomStringList);
+  if (aCopy.mString)
+    mString = nsCRT::strdup(aCopy.mString);
+  NS_IF_COPY(mNext, aCopy.mNext, nsAtomStringList);
+}
+
+nsAtomStringList::~nsAtomStringList(void)
+{
+  MOZ_COUNT_DTOR(nsAtomStringList);
+  if (mString)
+    nsCRT::free(mString);
+  NS_IF_DELETE(mNext);
+}
+
+PRBool nsAtomStringList::Equals(const nsAtomStringList* aOther) const
+{
+  return (this == aOther) ||
+         (aOther &&
+          mAtom == aOther->mAtom &&
+          !mString == !aOther->mString &&
+          !mNext == !aOther->mNext &&
+          (!mNext || mNext->Equals(aOther->mNext)) &&
+          // Check strings last, since it's the slowest check.
+          (!mString || nsDependentString(mString).Equals(
+                                        nsDependentString(aOther->mString),
+                                        nsCaseInsensitiveStringComparator())));
+}
+
 MOZ_DECL_CTOR_COUNTER(nsAttrSelector)
 
 #ifdef DEBUG_REFS
@@ -336,10 +391,9 @@ nsCSSSelector::nsCSSSelector(const nsCSSSelector& aCopy)
     mNext(nsnull)
 {
   MOZ_COUNT_CTOR(nsCSSSelector);
-  NS_IF_ADDREF(mTag);
   NS_IF_COPY(mIDList, aCopy.mIDList, nsAtomList);
   NS_IF_COPY(mClassList, aCopy.mClassList, nsAtomList);
-  NS_IF_COPY(mPseudoClassList, aCopy.mPseudoClassList, nsAtomList);
+  NS_IF_COPY(mPseudoClassList, aCopy.mPseudoClassList, nsAtomStringList);
   NS_IF_COPY(mAttrList, aCopy.mAttrList, nsAttrSelector);
   NS_IF_COPY(mNegations, aCopy.mNegations, nsCSSSelector);
   
@@ -362,7 +416,6 @@ nsCSSSelector::~nsCSSSelector(void)
 
 nsCSSSelector& nsCSSSelector::operator=(const nsCSSSelector& aCopy)
 {
-  NS_IF_RELEASE(mTag);
   NS_IF_DELETE(mIDList);
   NS_IF_DELETE(mClassList);
   NS_IF_DELETE(mPseudoClassList);
@@ -373,12 +426,11 @@ nsCSSSelector& nsCSSSelector::operator=(const nsCSSSelector& aCopy)
   mTag          = aCopy.mTag;
   NS_IF_COPY(mIDList, aCopy.mIDList, nsAtomList);
   NS_IF_COPY(mClassList, aCopy.mClassList, nsAtomList);
-  NS_IF_COPY(mPseudoClassList, aCopy.mPseudoClassList, nsAtomList);
+  NS_IF_COPY(mPseudoClassList, aCopy.mPseudoClassList, nsAtomStringList);
   NS_IF_COPY(mAttrList, aCopy.mAttrList, nsAttrSelector);
   mOperator     = aCopy.mOperator;
   NS_IF_COPY(mNegations, aCopy.mNegations, nsCSSSelector);
 
-  NS_IF_ADDREF(mTag);
   return *this;
 }
 
@@ -446,7 +498,7 @@ PRBool nsCSSSelector::Equals(const nsCSSSelector* aOther) const
 void nsCSSSelector::Reset(void)
 {
   mNameSpace = kNameSpaceID_Unknown;
-  NS_IF_RELEASE(mTag);
+  mTag = nsnull;
   NS_IF_DELETE(mIDList);
   NS_IF_DELETE(mClassList);
   NS_IF_DELETE(mPseudoClassList);
@@ -462,10 +514,10 @@ void nsCSSSelector::SetNameSpace(PRInt32 aNameSpace)
 
 void nsCSSSelector::SetTag(const nsString& aTag)
 {
-  NS_IF_RELEASE(mTag);
-  if (!aTag.IsEmpty()) {
-    mTag = NS_NewAtom(aTag);
-  }
+  if (aTag.IsEmpty())
+    mTag = nsnull;
+  else
+    mTag = do_GetAtom(aTag);
 }
 
 void nsCSSSelector::AddID(const nsString& aID)
@@ -490,25 +542,27 @@ void nsCSSSelector::AddClass(const nsString& aClass)
   }
 }
 
-void nsCSSSelector::AddPseudoClass(const nsString& aPseudoClass)
+void nsCSSSelector::AddPseudoClass(const nsString& aPseudoClass,
+                                   const PRUnichar* aString)
 {
   if (!aPseudoClass.IsEmpty()) {
-    nsAtomList** list = &mPseudoClassList;
+    nsAtomStringList** list = &mPseudoClassList;
     while (nsnull != *list) {
       list = &((*list)->mNext);
     }
-    *list = new nsAtomList(aPseudoClass);
+    *list = new nsAtomStringList(aPseudoClass, aString);
   }
 }
 
-void nsCSSSelector::AddPseudoClass(nsIAtom* aPseudoClass)
+void nsCSSSelector::AddPseudoClass(nsIAtom* aPseudoClass,
+                                   const PRUnichar* aString)
 {
   if (nsnull != aPseudoClass) {
-    nsAtomList** list = &mPseudoClassList;
+    nsAtomStringList** list = &mPseudoClassList;
     while (nsnull != *list) {
       list = &((*list)->mNext);
     }
-    *list = new nsAtomList(aPseudoClass);
+    *list = new nsAtomStringList(aPseudoClass, aString);
   }
 }
 
@@ -557,10 +611,10 @@ PRInt32 nsCSSSelector::CalcWeight(void) const
     weight += 0x000100;
     list = list->mNext;
   }
-  list = mPseudoClassList;
-  while (nsnull != list) {
+  nsAtomStringList *plist = mPseudoClassList;
+  while (nsnull != plist) {
     weight += 0x000100;
-    list = list->mNext;
+    plist = plist->mNext;
   }
   nsAttrSelector* attr = mAttrList;
   while (nsnull != attr) {
@@ -647,7 +701,7 @@ void nsCSSSelector::SizeOf(nsISizeOfHandler *aSizeOfHandler, PRUint32 &aSize)
     }
   }
   if(mPseudoClassList && uniqueItems->AddItem(mPseudoClassList)){
-    nsAtomList *pNext = nsnull;
+    nsAtomStringList *pNext = nsnull;
     pNext = mPseudoClassList;    
     while(pNext){
       if(pNext->mAtom && uniqueItems->AddItem(pNext->mAtom)){
@@ -832,11 +886,16 @@ nsresult nsCSSSelector::ToString( nsAString& aString, nsICSSStyleSheet* aSheet,
 
   // Append each pseudo-class in the linked list
   if (mPseudoClassList) {
-    nsAtomList* list = mPseudoClassList;
+    nsAtomStringList* list = mPseudoClassList;
     while (list != nsnull) {
       list->mAtom->GetUnicode(&temp);
       NS_IF_NEGATED_START(aIsNegated, aString)
       aString.Append(temp);
+      if (nsnull != list->mString) {
+        aString.Append(PRUnichar('('));
+        aString.Append(list->mString);
+        aString.Append(PRUnichar(')'));
+      }
       NS_IF_NEGATED_END(aIsNegated, aString)
       list = list->mNext;
     }
diff --git a/mozilla/layout/style/nsCSSStyleSheet.cpp b/mozilla/layout/style/nsCSSStyleSheet.cpp
index a7ecbb6e5a8..5785d7af8c1 100644
--- a/mozilla/layout/style/nsCSSStyleSheet.cpp
+++ b/mozilla/layout/style/nsCSSStyleSheet.cpp
@@ -245,7 +245,7 @@ RuleHash_CIMatchEntry(PLDHashTable *table, const PLDHashEntryHdr *hdr,
   nsIAtom *entry_atom = NS_CONST_CAST(nsIAtom*, NS_STATIC_CAST(const nsIAtom*,
              table->ops->getKey(table, NS_CONST_CAST(PLDHashEntryHdr*, hdr))));
 
-  // Check for case-insensitive match first.
+  // Check for case-sensitive match first.
   if (match_atom == entry_atom)
     return PR_TRUE;
 
@@ -2065,7 +2065,7 @@ CSSStyleSheetImpl::ClearMedia(void)
 NS_IMETHODIMP
 CSSStyleSheetImpl::GetEnabled(PRBool& aEnabled) const
 {
-  aEnabled = ((PR_TRUE == mDisabled) ? PR_FALSE : PR_TRUE);
+  aEnabled = !mDisabled;
   return NS_OK;
 }
 
@@ -2073,7 +2073,7 @@ NS_IMETHODIMP
 CSSStyleSheetImpl::SetEnabled(PRBool aEnabled)
 {
   PRBool oldState = mDisabled;
-  mDisabled = ((PR_TRUE == aEnabled) ? PR_FALSE : PR_TRUE);
+  mDisabled = !aEnabled;
 
   if ((nsnull != mDocument) && (mDisabled != oldState)) {
     mDocument->SetStyleSheetDisabledState(this, mDisabled);
@@ -2353,6 +2353,16 @@ CSSStyleSheetImpl::CheckRuleForAttributes(nsICSSRule *aRule)
           DependentAtomKey key(sel->mAttr);
           mInner->mRelevantAttributes.Put(&key, sel->mAttr);
         }
+
+        // Search for the :lang() pseudo class.  If it is there add
+        // the lang attribute to the relevant attribute list.
+        for (nsAtomStringList* p = iter->mPseudoClassList; p; p = p->mNext) {
+          if (p->mAtom == nsCSSAtoms::langPseudo) {
+            DependentAtomKey langKey(nsHTMLAtoms::lang);
+            mInner->mRelevantAttributes.Put(&langKey, nsHTMLAtoms::lang);
+            break;
+          }
+        }
       }
     } /* fall-through */
     default:
@@ -3373,6 +3383,7 @@ RuleProcessorData::RuleProcessorData(nsIPresContext* aPresContext,
   mNameSpaceID = kNameSpaceID_Unknown;
   mPreviousSiblingData = nsnull;
   mParentData = nsnull;
+  mIsLanguageValid = PR_FALSE;
 
   // get the compat. mode (unless it is provided)
   if(!aCompat) {
@@ -3418,7 +3429,7 @@ RuleProcessorData::RuleProcessorData(nsIPresContext* aPresContext,
 
     // if HTML content and it has some attributes, check for an HTML link
     // NOTE: optimization: cannot be a link if no attributes (since it needs an href)
-    if (PR_TRUE == mIsHTMLContent && mHasAttributes) {
+    if (mIsHTMLContent && mHasAttributes) {
       // check if it is an HTML Link
       if(nsStyleUtil::IsHTMLLink(aContent, mContentTag, mPresContext, &mLinkState)) {
         mIsHTMLLink = PR_TRUE;
@@ -3427,9 +3438,9 @@ RuleProcessorData::RuleProcessorData(nsIPresContext* aPresContext,
 
     // if not an HTML link, check for a simple xlink (cannot be both HTML link and xlink)
     // NOTE: optimization: cannot be an XLink if no attributes (since it needs an 
-    if(PR_FALSE == mIsHTMLLink &&
+    if(!mIsHTMLLink &&
        mHasAttributes && 
-       !(aContent->IsContentOfType(nsIContent::eHTML) || aContent->IsContentOfType(nsIContent::eXUL)) && 
+       !(mIsHTMLContent || aContent->IsContentOfType(nsIContent::eXUL)) && 
        nsStyleUtil::IsSimpleXlink(aContent, mPresContext, &mLinkState)) {
       mIsSimpleXLink = PR_TRUE;
     } 
@@ -3463,6 +3474,39 @@ RuleProcessorData::~RuleProcessorData()
   NS_IF_RELEASE(mStyledContent);
 }
 
+const nsString* RuleProcessorData::GetLang(void)
+{
+  if (!mIsLanguageValid) {
+    mIsLanguageValid = PR_TRUE;
+    mLanguage.SetLength(0);
+    nsCOMPtr<nsIContent> content = mContent;
+    while (content) {
+      PRInt32 attrCount = 0;
+      content->GetAttrCount(attrCount);
+      if (attrCount > 0) {
+        // xml:lang has precedence over lang on HTML elements (see
+        // XHTML1 section C.7).
+        nsAutoString value;
+        nsresult attrState = content->GetAttr(kNameSpaceID_XML,
+                                              nsHTMLAtoms::lang, value);
+        if (attrState != NS_CONTENT_ATTR_HAS_VALUE &&
+            content->IsContentOfType(nsIContent::eHTML)) {
+          attrState = content->GetAttr(kNameSpaceID_None,
+                                       nsHTMLAtoms::lang, value);
+        }
+        if (attrState == NS_CONTENT_ATTR_HAS_VALUE) {
+          mLanguage = value;
+          break;
+        }
+      }
+      nsIContent *parent;
+      content->GetParent(parent);
+      content = dont_AddRef(parent);
+    }
+  }
+  return &mLanguage;
+}
+
 static const PRUnichar kNullCh = PRUnichar('\0');
 
 static PRBool ValueIncludes(const nsString& aValueList, const nsString& aValue, PRBool aCaseSensitive)
@@ -3564,6 +3608,39 @@ static PRBool IsSignificantChild(nsIContent* aChild, PRBool aAcceptNonWhitespace
   return PR_FALSE;
 }
 
+static PRBool
+DashMatchCompare(const nsAString& aAttributeValue,
+                 const nsAString& aSelectorValue,
+                 const PRBool aCaseSensitive)
+{
+  PRBool result;
+  PRUint32 selectorLen = aSelectorValue.Length();
+  PRUint32 attributeLen = aAttributeValue.Length();
+  if (selectorLen > attributeLen) {
+    result = PR_FALSE;
+  }
+  else {
+    nsAString::const_iterator iter;
+    if (selectorLen != attributeLen &&
+        *aAttributeValue.BeginReading(iter).advance(selectorLen) !=
+            PRUnichar('-')) {
+      // to match, the aAttributeValue must have a dash after the end of
+      // the aSelectorValue's text (unless the aSelectorValue and the
+      // aAttributeValue have the same text)
+      result = PR_FALSE;
+    }
+    else {
+      const nsAString& attributeSubstring =
+        Substring(aAttributeValue, 0, selectorLen);
+      if (aCaseSensitive)
+        result = attributeSubstring.Equals(aSelectorValue);
+      else
+        result = attributeSubstring.Equals(aSelectorValue,
+                                          nsCaseInsensitiveStringComparator());
+    }
+  }
+  return result;
+}
 
 // NOTE:  The |aStateMask| code isn't going to work correctly anymore if
 // we start batching style changes, because if multiple states change in
@@ -3606,7 +3683,7 @@ static PRBool SelectorMatches(RuleProcessorData &data,
   if (nsnull != aSelector->mPseudoClassList) {  // test for pseudo class match
     // first-child, root, lang, active, focus, hover, link, visited...
     // XXX disabled, enabled, selected, selection
-    nsAtomList* pseudoClass = aSelector->mPseudoClassList;
+    nsAtomStringList* pseudoClass = aSelector->mPseudoClassList;
 
     while (result && (nsnull != pseudoClass)) {
       if ((nsCSSAtoms::firstChildPseudo == pseudoClass->mAtom) ||
@@ -3686,8 +3763,49 @@ static PRBool SelectorMatches(RuleProcessorData &data,
                    ? localTrue : localFalse;
       }
       else if (nsCSSAtoms::langPseudo == pseudoClass->mAtom) {
-        // XXX not yet implemented
-        result = PR_FALSE;
+        NS_ASSERTION(nsnull != pseudoClass->mString, "null lang parameter");
+        result = localFalse;
+        if (pseudoClass->mString && *pseudoClass->mString) {
+          // We have to determine the language of the current element.  Since
+          // this is currently no property and since the language is inherited
+          // from the parent we have to be prepared to look at all parent
+          // nodes.  The language itself is encoded in the LANG attribute.
+          const nsString* lang = data.GetLang();
+          if (!lang->IsEmpty()) {
+            result = localTrue == DashMatchCompare(*lang,
+                            nsDependentString(pseudoClass->mString), PR_FALSE);
+          }
+          else {
+            nsCOMPtr<nsIDocument> doc;
+            data.mContent->GetDocument(*getter_AddRefs(doc));
+            if (doc) {
+              // Try to get the language from the HTTP header or if this
+              // is missing as well from the preferences.
+              // The content language can be a comma-separated list of
+              // language codes.
+              nsAutoString language;
+              if (NS_SUCCEEDED(doc->GetContentLanguage(language))) {
+                nsDependentString langString(pseudoClass->mString);
+                language.StripWhitespace();
+                PRInt32 begin = 0;
+                PRInt32 len = language.Length();
+                while (begin < len) {
+                  PRInt32 end = language.FindChar(PRUnichar(','), begin);
+                  if (end == kNotFound) {
+                    end = len;
+                  }
+                  if (DashMatchCompare(Substring(language, begin, end-begin),
+                                       langString,
+                                       PR_FALSE)) {
+                    result = localTrue;
+                    break;
+                  }
+                  begin = end + 1;
+                }
+              }
+            }
+          }
+        }
       }
       else if (IsEventPseudo(pseudoClass->mAtom)) {
         // check if the element is event-sensitive
@@ -3783,36 +3901,17 @@ static PRBool SelectorMatches(RuleProcessorData &data,
           switch (attr->mFunction) {
             case NS_ATTR_FUNC_EQUALS: 
               if (isCaseSensitive) {
-                result = PRBool(localTrue == value.Equals(attr->mValue));
+                result = localTrue == value.Equals(attr->mValue);
               }
               else {
-                result = PRBool(localTrue == value.Equals(attr->mValue, nsCaseInsensitiveStringComparator()));
+                result = localTrue == value.Equals(attr->mValue, nsCaseInsensitiveStringComparator());
               }
               break;
             case NS_ATTR_FUNC_INCLUDES: 
-              result = PRBool(localTrue == ValueIncludes(value, attr->mValue, isCaseSensitive));
+              result = localTrue == ValueIncludes(value, attr->mValue, isCaseSensitive);
               break;
             case NS_ATTR_FUNC_DASHMATCH: 
-              {
-                PRUint32 selLen = attr->mValue.Length();
-                PRUint32 valLen = value.Length();
-                if (selLen > valLen) {
-                  result = localFalse;
-                } else {
-                  if (selLen != valLen &&
-                      value.CharAt(selLen) != PRUnichar('-')) {
-                    // to match, the value must have a dash after the end of
-                    // the selector's text (unless the selector and the value
-                    // have the same text)
-                    result = localFalse;
-                    break;
-                  }
-                  if (isCaseSensitive)
-                    result = PRBool(localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsDefaultStringComparator()));
-                  else
-                    result = PRBool(localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsCaseInsensitiveStringComparator()));
-                }
-              }
+              result = localTrue == DashMatchCompare(value, attr->mValue, isCaseSensitive);
               break;
             case NS_ATTR_FUNC_ENDSMATCH:
               {
@@ -3822,9 +3921,9 @@ static PRBool SelectorMatches(RuleProcessorData &data,
                   result = localFalse;
                 } else {
                   if (isCaseSensitive)
-                    result = PRBool(localTrue == Substring(value, valLen - selLen, selLen).Equals(attr->mValue, nsDefaultStringComparator()));
+                    result = localTrue == Substring(value, valLen - selLen, selLen).Equals(attr->mValue, nsDefaultStringComparator());
                   else
-                    result = PRBool(localTrue == Substring(value, valLen - selLen, selLen).Equals(attr->mValue, nsCaseInsensitiveStringComparator()));
+                    result = localTrue == Substring(value, valLen - selLen, selLen).Equals(attr->mValue, nsCaseInsensitiveStringComparator());
                 }
               }
               break;
@@ -3836,14 +3935,14 @@ static PRBool SelectorMatches(RuleProcessorData &data,
                   result = localFalse;
                 } else {
                   if (isCaseSensitive)
-                    result = PRBool(localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsDefaultStringComparator()));
+                    result = localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsDefaultStringComparator());
                   else
-                    result = PRBool(localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsCaseInsensitiveStringComparator()));
+                    result = localTrue == Substring(value, 0, selLen).Equals(attr->mValue, nsCaseInsensitiveStringComparator());
                 }
               }
               break;
             case NS_ATTR_FUNC_CONTAINSMATCH:
-              result = PRBool(localTrue == (FindInReadable(attr->mValue, value, nsCaseInsensitiveStringComparator())));
+              result = localTrue == (FindInReadable(attr->mValue, value, nsCaseInsensitiveStringComparator()));
               break;
           }
         }
@@ -4210,6 +4309,7 @@ PRBool WeightedRulesSizeEnumFunc( nsISupports *aRule, void *aData )
 {
   nsICSSStyleRule* rule = (nsICSSStyleRule*)aRule;
   CascadeSizeEnumData *pData = (CascadeSizeEnumData *)aData;
+
   NS_ASSERTION(rule && pData, "null arguments not supported");
 
   if(! pData->uniqueItems->AddItem((void*)rule)){
@@ -4335,7 +4435,7 @@ CSSRuleProcessor::ClearRuleCascades(void)
 inline
 PRBool IsStateSelector(nsCSSSelector& aSelector)
 {
-  nsAtomList* pseudoClass = aSelector.mPseudoClassList;
+  nsAtomStringList* pseudoClass = aSelector.mPseudoClassList;
   while (pseudoClass) {
     if ((pseudoClass->mAtom == nsCSSAtoms::activePseudo) ||
         (pseudoClass->mAtom == nsCSSAtoms::checkedPseudo) ||
diff --git a/mozilla/layout/style/nsICSSStyleRule.h b/mozilla/layout/style/nsICSSStyleRule.h
index 7d9e4e1b93f..f19ed554166 100644
--- a/mozilla/layout/style/nsICSSStyleRule.h
+++ b/mozilla/layout/style/nsICSSStyleRule.h
@@ -42,8 +42,10 @@
 //#include <stdio.h>
 #include "nsICSSRule.h"
 #include "nsString.h"
+#include "nsCOMPtr.h"
 #include "nsCSSProps.h"
 #include "nsCSSValue.h"
+#include "nsIAtom.h"
 
 class nsISizeOfHandler;
 
@@ -60,8 +62,21 @@ public:
   ~nsAtomList(void);
   PRBool Equals(const nsAtomList* aOther) const;
 
-  nsIAtom*    mAtom;
-  nsAtomList* mNext;
+  nsCOMPtr<nsIAtom> mAtom;
+  nsAtomList*       mNext;
+};
+
+struct nsAtomStringList {
+public:
+  nsAtomStringList(nsIAtom* aAtom, const PRUnichar *aString = nsnull);
+  nsAtomStringList(const nsString& aAtomValue, const PRUnichar *aString = nsnull);
+  nsAtomStringList(const nsAtomStringList& aCopy);
+  ~nsAtomStringList(void);
+  PRBool Equals(const nsAtomStringList* aOther) const;
+
+  nsCOMPtr<nsIAtom> mAtom;
+  PRUnichar*        mString;
+  nsAtomStringList* mNext;
 };
 
 #define NS_ATTR_FUNC_SET        0     // [attr]
@@ -112,8 +127,8 @@ public:
   void SetTag(const nsString& aTag);
   void AddID(const nsString& aID);
   void AddClass(const nsString& aClass);
-  void AddPseudoClass(const nsString& aPseudoClass);
-  void AddPseudoClass(nsIAtom* aPseudoClass);
+  void AddPseudoClass(const nsString& aPseudoClass, const PRUnichar* aString = nsnull);
+  void AddPseudoClass(nsIAtom* aPseudoClass, const PRUnichar* aString = nsnull);
   void AddAttribute(PRInt32 aNameSpace, const nsString& aAttr);
   void AddAttribute(PRInt32 aNameSpace, const nsString& aAttr, PRUint8 aFunc, 
                     const nsString& aValue, PRBool aCaseSensitive);
@@ -133,10 +148,11 @@ private:
 
 public:
   PRInt32         mNameSpace;
-  nsIAtom*        mTag;
+  nsCOMPtr<nsIAtom> mTag;
   nsAtomList*     mIDList;
   nsAtomList*     mClassList;
-  nsAtomList*     mPseudoClassList;
+  nsAtomStringList* mPseudoClassList; // atom for the pseudo, string for
+                                      // the argument to functional pseudos
   nsAttrSelector* mAttrList;
   PRUnichar       mOperator;
   nsCSSSelector*  mNegations;
diff --git a/mozilla/layout/style/nsIStyleRuleProcessor.h b/mozilla/layout/style/nsIStyleRuleProcessor.h
index c3e7cb4c1f4..78e612019b8 100644
--- a/mozilla/layout/style/nsIStyleRuleProcessor.h
+++ b/mozilla/layout/style/nsIStyleRuleProcessor.h
@@ -43,6 +43,7 @@
 #include "nsISupports.h"
 #include "nsIPresContext.h" // for nsCompatability
 #include "nsILinkHandler.h"
+#include "nsString.h"
 
 class nsISizeOfHandler;
 
@@ -78,6 +79,8 @@ struct RuleProcessorData {
     aContext->FreeToShell(sizeof(RuleProcessorData), this);
   };
 
+  const nsString* GetLang();
+
   nsIPresContext*   mPresContext;
   nsIContent*       mContent;
   nsIContent*       mParentContent; // if content, content->GetParent()
@@ -98,6 +101,10 @@ struct RuleProcessorData {
   PRInt32           mNameSpaceID;   // if content, content->GetNameSapce()
   RuleProcessorData* mPreviousSiblingData;
   RuleProcessorData* mParentData;
+
+protected:
+  nsAutoString mLanguage;
+  PRBool mIsLanguageValid;
 };
 
 struct ElementRuleProcessorData : public RuleProcessorData {
diff --git a/mozilla/layout/style/nsStyleContext.cpp b/mozilla/layout/style/nsStyleContext.cpp
index 3bc83916c92..bd760db159a 100644
--- a/mozilla/layout/style/nsStyleContext.cpp
+++ b/mozilla/layout/style/nsStyleContext.cpp
@@ -565,7 +565,7 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, PRInt32& aHint)
     
     // We begin by examining those style structs that are capable of causing the maximal
     // difference, a FRAMECHANGE.
-    // FRAMECHANGE Structs: Display, XUL, Content, UserInterface
+    // FRAMECHANGE Structs: Display, XUL, Content, UserInterface, Quotes
     if (aHint < maxHint) {
       const nsStyleDisplay* display = (const nsStyleDisplay*)PeekStyleData(eStyleStruct_Display);
       if (display) {
@@ -630,12 +630,26 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, PRInt32& aHint)
     }
 #endif
 
+    // If the quotes implementation is ever going to change we might not need
+    // a framechange here and a reflow should be sufficient.  See bug 35768.
+    if (aHint < maxHint) {
+      const nsStyleQuotes* quotes = (const nsStyleQuotes*)PeekStyleData(eStyleStruct_Quotes);
+      if (quotes) {
+        const nsStyleQuotes* otherQuotes = (const nsStyleQuotes*)aOther->GetStyleData(eStyleStruct_Quotes);
+        if (quotes != otherQuotes) {
+          hint = quotes->CalcDifference(*otherQuotes);
+          if (aHint < hint)
+            aHint = hint;
+        }
+      }
+    }
+
     // At this point, we know that the worst kind of damage we could do is a reflow.
     maxHint = NS_STYLE_HINT_REFLOW;
         
     // The following structs cause (as their maximal difference) a reflow to occur.
     // REFLOW Structs: Font, Margin, Padding, Border, List, Position, Text, TextReset,
-    // Visibility, Quotes, Table, TableBorder
+    // Visibility, Table, TableBorder
     if (aHint < maxHint) {
       const nsStyleFont* font = (const nsStyleFont*)PeekStyleData(eStyleStruct_Font);
       if (font) {
@@ -768,18 +782,6 @@ nsStyleContext::CalcStyleDifference(nsIStyleContext* aOther, PRInt32& aHint)
       }
     }
 
-    if (aHint < maxHint) {
-      const nsStyleQuotes* quotes = (const nsStyleQuotes*)PeekStyleData(eStyleStruct_Quotes);
-      if (quotes) {
-        const nsStyleQuotes* otherQuotes = (const nsStyleQuotes*)aOther->GetStyleData(eStyleStruct_Quotes);
-        if (quotes != otherQuotes) {
-          hint = quotes->CalcDifference(*otherQuotes);
-          if (aHint < hint)
-            aHint = hint;
-        }
-      }
-    }
-
     // At this point, we know that the worst kind of damage we could do is a re-render
     // (i.e., a VISUAL change).
     maxHint = NS_STYLE_HINT_VISUAL;
diff --git a/mozilla/layout/style/nsStyleStruct.cpp b/mozilla/layout/style/nsStyleStruct.cpp
index f8ca3208f5d..c9660ee1377 100644
--- a/mozilla/layout/style/nsStyleStruct.cpp
+++ b/mozilla/layout/style/nsStyleStruct.cpp
@@ -1246,17 +1246,19 @@ nsStyleQuotes::nsStyleQuotes(const nsStyleQuotes& aSource)
 PRInt32 
 nsStyleQuotes::CalcDifference(const nsStyleQuotes& aOther) const
 {
+  // If the quotes implementation is ever going to change we might not need
+  // a framechange here and a reflow should be sufficient.  See bug 35768.
   if (mQuotesCount == aOther.mQuotesCount) {
     PRUint32 ix = (mQuotesCount * 2);
     while (0 < ix--) {
       if (mQuotes[ix] != aOther.mQuotes[ix]) {
-        return NS_STYLE_HINT_REFLOW;
+        return NS_STYLE_HINT_FRAMECHANGE;
       }
     }
 
     return NS_STYLE_HINT_NONE;
   }
-  return NS_STYLE_HINT_REFLOW;
+  return NS_STYLE_HINT_FRAMECHANGE;
 }
 
 // --------------------
diff --git a/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp b/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
index 3b81b1b8ab3..47ee1c0efe7 100644
--- a/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
+++ b/mozilla/layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
@@ -3306,7 +3306,7 @@ nsTreeBodyFrame::PseudoMatches(nsIAtom* aTag, nsCSSSelector* aSelector, PRBool*
     // it is contained in our scratch array.  If we have a miss, then
     // we aren't a match.  If all items in the pseudoclass list are
     // present in the scratch array, then we have a match.
-    nsAtomList* curr = aSelector->mPseudoClassList;
+    nsAtomStringList* curr = aSelector->mPseudoClassList;
     while (curr) {
       PRInt32 index;
       mScratchArray->GetIndexOf(curr->mAtom, &index);