diff --git a/mozilla/string/obsolete/nsString.h b/mozilla/string/obsolete/nsString.h
index 47402f69ef8..ca40d024a8a 100644
--- a/mozilla/string/obsolete/nsString.h
+++ b/mozilla/string/obsolete/nsString.h
@@ -808,7 +808,7 @@ private:
   void InsertWithConversion( char, PRUint32 );
 };
 
-#ifdef NEW_STRING_APIS
+#if 0 // #ifdef NEW_STRING_APIS
 inline
 nsPromiseConcatenation<char>
 operator+( const nsPromiseConcatenation<char>& lhs, const nsCString& rhs )
@@ -819,7 +819,7 @@ operator+( const nsPromiseConcatenation<char>& lhs, const nsCString& rhs )
 
 #ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsCString, char)
-NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsCString, char);
+// NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsCString, char);
 #endif
 
 extern NS_COM int fputs(const nsCString& aString, FILE* out);
diff --git a/mozilla/string/obsolete/nsString2.h b/mozilla/string/obsolete/nsString2.h
index e40d5e6652b..754598dc182 100644
--- a/mozilla/string/obsolete/nsString2.h
+++ b/mozilla/string/obsolete/nsString2.h
@@ -896,10 +896,10 @@ private:
 
 #ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsString, PRUnichar)
-NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsString, PRUnichar)
+// NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsString, PRUnichar)
 #endif
 
-#ifdef NEW_STRING_APIS
+#if 0 // #ifdef NEW_STRING_APIS
 inline
 nsPromiseConcatenation<PRUnichar>
 operator+( const nsPromiseConcatenation<PRUnichar>& lhs, const nsString& rhs )
diff --git a/mozilla/string/public/nsAReadableString.h b/mozilla/string/public/nsAReadableString.h
index bf4b2796d44..f0862e8db6a 100644
--- a/mozilla/string/public/nsAReadableString.h
+++ b/mozilla/string/public/nsAReadableString.h
@@ -950,7 +950,9 @@ class nsPromiseConcatenation
       virtual PRBool Promises( const basic_nsAReadableString<CharT>& ) const;
 //    virtual PRBool PromisesExactly( const basic_nsAReadableString<CharT>& ) const;
 
-      nsPromiseConcatenation<CharT> operator+( const basic_nsAReadableString<CharT>& rhs ) const;
+//    nsPromiseConcatenation<CharT> operator+( const basic_nsAReadableString<CharT>& rhs ) const;
+
+      PRUint32 GetFragmentIdentifierMask() const { return mFragmentIdentifierMask; }
 
     private:
       void operator+( const nsPromiseConcatenation<CharT>& ); // NOT TO BE IMPLEMENTED
@@ -1051,6 +1053,7 @@ nsPromiseConcatenation<CharT>::GetReadableFragment( nsReadableFragment<CharT>& a
     return result;
   }
 
+#if 0
 template <class CharT>
 inline
 nsPromiseConcatenation<CharT>
@@ -1058,7 +1061,7 @@ nsPromiseConcatenation<CharT>::operator+( const basic_nsAReadableString<CharT>&
   {
     return nsPromiseConcatenation<CharT>(*this, rhs, mFragmentIdentifierMask<<1);
   }
-
+#endif
 
 
 
@@ -1271,6 +1274,14 @@ Compare( const CharT* lhs, const basic_nsAReadableString<CharT>& rhs )
     automatic conversion to a literal string will not happen.
   */
 
+template <class CharT>
+inline
+nsPromiseConcatenation<CharT>
+operator+( const nsPromiseConcatenation<CharT>& lhs, const basic_nsAReadableString<CharT>& rhs )
+  {
+    return nsPromiseConcatenation<CharT>(lhs, rhs, lhs.GetFragmentIdentifierMask());
+  }
+
 template <class CharT>
 inline
 nsPromiseConcatenation<CharT>
@@ -1279,6 +1290,8 @@ operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsAReadableStr
     return nsPromiseConcatenation<CharT>(lhs, rhs);
   }
 
+
+
 #ifdef NEED_CPP_DERIVED_TEMPLATE_OPERATORS
   #define NS_DEF_DERIVED_STRING_STRING_OPERATOR_PLUS(_String1T, _String2T, _CharT) \
     inline                                                  \
@@ -1300,29 +1313,6 @@ operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsAReadableStr
   #define NS_DEF_2_STRING_STRING_OPERATOR_PLUS(_String1T, _String2T, _CharT)
 #endif
 
-template <class CharT>
-inline
-nsPromiseConcatenation<CharT>
-operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsLiteralString<CharT>& rhs )
-  {
-    return nsPromiseConcatenation<CharT>(lhs, rhs);
-  }
-
-template <class CharT>
-inline
-nsPromiseConcatenation<CharT>
-operator+( const basic_nsLiteralString<CharT>& lhs, const basic_nsAReadableString<CharT>& rhs )
-  {
-    return nsPromiseConcatenation<CharT>(lhs, rhs);
-  }
-
-template <class CharT>
-inline
-nsPromiseConcatenation<CharT>
-operator+( const basic_nsLiteralString<CharT>& lhs, const basic_nsLiteralString<CharT>& rhs )
-  {
-    return nsPromiseConcatenation<CharT>(lhs, rhs);
-  }
 
 #define kDefaultFlatStringSize 64
 
diff --git a/mozilla/xpcom/ds/nsAReadableString.h b/mozilla/xpcom/ds/nsAReadableString.h
index bf4b2796d44..f0862e8db6a 100644
--- a/mozilla/xpcom/ds/nsAReadableString.h
+++ b/mozilla/xpcom/ds/nsAReadableString.h
@@ -950,7 +950,9 @@ class nsPromiseConcatenation
       virtual PRBool Promises( const basic_nsAReadableString<CharT>& ) const;
 //    virtual PRBool PromisesExactly( const basic_nsAReadableString<CharT>& ) const;
 
-      nsPromiseConcatenation<CharT> operator+( const basic_nsAReadableString<CharT>& rhs ) const;
+//    nsPromiseConcatenation<CharT> operator+( const basic_nsAReadableString<CharT>& rhs ) const;
+
+      PRUint32 GetFragmentIdentifierMask() const { return mFragmentIdentifierMask; }
 
     private:
       void operator+( const nsPromiseConcatenation<CharT>& ); // NOT TO BE IMPLEMENTED
@@ -1051,6 +1053,7 @@ nsPromiseConcatenation<CharT>::GetReadableFragment( nsReadableFragment<CharT>& a
     return result;
   }
 
+#if 0
 template <class CharT>
 inline
 nsPromiseConcatenation<CharT>
@@ -1058,7 +1061,7 @@ nsPromiseConcatenation<CharT>::operator+( const basic_nsAReadableString<CharT>&
   {
     return nsPromiseConcatenation<CharT>(*this, rhs, mFragmentIdentifierMask<<1);
   }
-
+#endif
 
 
 
@@ -1271,6 +1274,14 @@ Compare( const CharT* lhs, const basic_nsAReadableString<CharT>& rhs )
     automatic conversion to a literal string will not happen.
   */
 
+template <class CharT>
+inline
+nsPromiseConcatenation<CharT>
+operator+( const nsPromiseConcatenation<CharT>& lhs, const basic_nsAReadableString<CharT>& rhs )
+  {
+    return nsPromiseConcatenation<CharT>(lhs, rhs, lhs.GetFragmentIdentifierMask());
+  }
+
 template <class CharT>
 inline
 nsPromiseConcatenation<CharT>
@@ -1279,6 +1290,8 @@ operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsAReadableStr
     return nsPromiseConcatenation<CharT>(lhs, rhs);
   }
 
+
+
 #ifdef NEED_CPP_DERIVED_TEMPLATE_OPERATORS
   #define NS_DEF_DERIVED_STRING_STRING_OPERATOR_PLUS(_String1T, _String2T, _CharT) \
     inline                                                  \
@@ -1300,29 +1313,6 @@ operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsAReadableStr
   #define NS_DEF_2_STRING_STRING_OPERATOR_PLUS(_String1T, _String2T, _CharT)
 #endif
 
-template <class CharT>
-inline
-nsPromiseConcatenation<CharT>
-operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsLiteralString<CharT>& rhs )
-  {
-    return nsPromiseConcatenation<CharT>(lhs, rhs);
-  }
-
-template <class CharT>
-inline
-nsPromiseConcatenation<CharT>
-operator+( const basic_nsLiteralString<CharT>& lhs, const basic_nsAReadableString<CharT>& rhs )
-  {
-    return nsPromiseConcatenation<CharT>(lhs, rhs);
-  }
-
-template <class CharT>
-inline
-nsPromiseConcatenation<CharT>
-operator+( const basic_nsLiteralString<CharT>& lhs, const basic_nsLiteralString<CharT>& rhs )
-  {
-    return nsPromiseConcatenation<CharT>(lhs, rhs);
-  }
 
 #define kDefaultFlatStringSize 64
 
diff --git a/mozilla/xpcom/ds/nsString.h b/mozilla/xpcom/ds/nsString.h
index 47402f69ef8..ca40d024a8a 100644
--- a/mozilla/xpcom/ds/nsString.h
+++ b/mozilla/xpcom/ds/nsString.h
@@ -808,7 +808,7 @@ private:
   void InsertWithConversion( char, PRUint32 );
 };
 
-#ifdef NEW_STRING_APIS
+#if 0 // #ifdef NEW_STRING_APIS
 inline
 nsPromiseConcatenation<char>
 operator+( const nsPromiseConcatenation<char>& lhs, const nsCString& rhs )
@@ -819,7 +819,7 @@ operator+( const nsPromiseConcatenation<char>& lhs, const nsCString& rhs )
 
 #ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsCString, char)
-NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsCString, char);
+// NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsCString, char);
 #endif
 
 extern NS_COM int fputs(const nsCString& aString, FILE* out);
diff --git a/mozilla/xpcom/ds/nsString2.h b/mozilla/xpcom/ds/nsString2.h
index e40d5e6652b..754598dc182 100644
--- a/mozilla/xpcom/ds/nsString2.h
+++ b/mozilla/xpcom/ds/nsString2.h
@@ -896,10 +896,10 @@ private:
 
 #ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsString, PRUnichar)
-NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsString, PRUnichar)
+// NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsString, PRUnichar)
 #endif
 
-#ifdef NEW_STRING_APIS
+#if 0 // #ifdef NEW_STRING_APIS
 inline
 nsPromiseConcatenation<PRUnichar>
 operator+( const nsPromiseConcatenation<PRUnichar>& lhs, const nsString& rhs )
diff --git a/mozilla/xpcom/string/obsolete/nsString.h b/mozilla/xpcom/string/obsolete/nsString.h
index 47402f69ef8..ca40d024a8a 100644
--- a/mozilla/xpcom/string/obsolete/nsString.h
+++ b/mozilla/xpcom/string/obsolete/nsString.h
@@ -808,7 +808,7 @@ private:
   void InsertWithConversion( char, PRUint32 );
 };
 
-#ifdef NEW_STRING_APIS
+#if 0 // #ifdef NEW_STRING_APIS
 inline
 nsPromiseConcatenation<char>
 operator+( const nsPromiseConcatenation<char>& lhs, const nsCString& rhs )
@@ -819,7 +819,7 @@ operator+( const nsPromiseConcatenation<char>& lhs, const nsCString& rhs )
 
 #ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsCString, char)
-NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsCString, char);
+// NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsCString, char);
 #endif
 
 extern NS_COM int fputs(const nsCString& aString, FILE* out);
diff --git a/mozilla/xpcom/string/obsolete/nsString2.h b/mozilla/xpcom/string/obsolete/nsString2.h
index e40d5e6652b..754598dc182 100644
--- a/mozilla/xpcom/string/obsolete/nsString2.h
+++ b/mozilla/xpcom/string/obsolete/nsString2.h
@@ -896,10 +896,10 @@ private:
 
 #ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsString, PRUnichar)
-NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsString, PRUnichar)
+// NS_DEF_DERIVED_STRING_OPERATOR_PLUS(nsString, PRUnichar)
 #endif
 
-#ifdef NEW_STRING_APIS
+#if 0 // #ifdef NEW_STRING_APIS
 inline
 nsPromiseConcatenation<PRUnichar>
 operator+( const nsPromiseConcatenation<PRUnichar>& lhs, const nsString& rhs )
diff --git a/mozilla/xpcom/string/public/nsAReadableString.h b/mozilla/xpcom/string/public/nsAReadableString.h
index bf4b2796d44..f0862e8db6a 100644
--- a/mozilla/xpcom/string/public/nsAReadableString.h
+++ b/mozilla/xpcom/string/public/nsAReadableString.h
@@ -950,7 +950,9 @@ class nsPromiseConcatenation
       virtual PRBool Promises( const basic_nsAReadableString<CharT>& ) const;
 //    virtual PRBool PromisesExactly( const basic_nsAReadableString<CharT>& ) const;
 
-      nsPromiseConcatenation<CharT> operator+( const basic_nsAReadableString<CharT>& rhs ) const;
+//    nsPromiseConcatenation<CharT> operator+( const basic_nsAReadableString<CharT>& rhs ) const;
+
+      PRUint32 GetFragmentIdentifierMask() const { return mFragmentIdentifierMask; }
 
     private:
       void operator+( const nsPromiseConcatenation<CharT>& ); // NOT TO BE IMPLEMENTED
@@ -1051,6 +1053,7 @@ nsPromiseConcatenation<CharT>::GetReadableFragment( nsReadableFragment<CharT>& a
     return result;
   }
 
+#if 0
 template <class CharT>
 inline
 nsPromiseConcatenation<CharT>
@@ -1058,7 +1061,7 @@ nsPromiseConcatenation<CharT>::operator+( const basic_nsAReadableString<CharT>&
   {
     return nsPromiseConcatenation<CharT>(*this, rhs, mFragmentIdentifierMask<<1);
   }
-
+#endif
 
 
 
@@ -1271,6 +1274,14 @@ Compare( const CharT* lhs, const basic_nsAReadableString<CharT>& rhs )
     automatic conversion to a literal string will not happen.
   */
 
+template <class CharT>
+inline
+nsPromiseConcatenation<CharT>
+operator+( const nsPromiseConcatenation<CharT>& lhs, const basic_nsAReadableString<CharT>& rhs )
+  {
+    return nsPromiseConcatenation<CharT>(lhs, rhs, lhs.GetFragmentIdentifierMask());
+  }
+
 template <class CharT>
 inline
 nsPromiseConcatenation<CharT>
@@ -1279,6 +1290,8 @@ operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsAReadableStr
     return nsPromiseConcatenation<CharT>(lhs, rhs);
   }
 
+
+
 #ifdef NEED_CPP_DERIVED_TEMPLATE_OPERATORS
   #define NS_DEF_DERIVED_STRING_STRING_OPERATOR_PLUS(_String1T, _String2T, _CharT) \
     inline                                                  \
@@ -1300,29 +1313,6 @@ operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsAReadableStr
   #define NS_DEF_2_STRING_STRING_OPERATOR_PLUS(_String1T, _String2T, _CharT)
 #endif
 
-template <class CharT>
-inline
-nsPromiseConcatenation<CharT>
-operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsLiteralString<CharT>& rhs )
-  {
-    return nsPromiseConcatenation<CharT>(lhs, rhs);
-  }
-
-template <class CharT>
-inline
-nsPromiseConcatenation<CharT>
-operator+( const basic_nsLiteralString<CharT>& lhs, const basic_nsAReadableString<CharT>& rhs )
-  {
-    return nsPromiseConcatenation<CharT>(lhs, rhs);
-  }
-
-template <class CharT>
-inline
-nsPromiseConcatenation<CharT>
-operator+( const basic_nsLiteralString<CharT>& lhs, const basic_nsLiteralString<CharT>& rhs )
-  {
-    return nsPromiseConcatenation<CharT>(lhs, rhs);
-  }
 
 #define kDefaultFlatStringSize 64