diff --git a/mozilla/modules/libpref/public/nsIPref.idl b/mozilla/modules/libpref/public/nsIPref.idl
index df61f8c36a0..ceca1bad6b5 100644
--- a/mozilla/modules/libpref/public/nsIPref.idl
+++ b/mozilla/modules/libpref/public/nsIPref.idl
@@ -1,4 +1,4 @@
-/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
  *
  * The contents of this file are subject to the Netscape Public
  * License Version 1.1 (the "License"); you may not use this file
@@ -138,6 +138,7 @@ interface nsIPref : nsISupports {
 
   /* set defaults */
   void SetDefaultCharPref(in string pref, in string value);
+  void SetDefaultUnicharPref(in string pref, in wstring value);
   void SetDefaultIntPref(in string pref, in long value);
   void SetDefaultBoolPref(in string pref, in boolean value);
   [noscript] void SetDefaultBinaryPref(in string pref, in voidStar value, in unsigned long size);
@@ -153,6 +154,7 @@ interface nsIPref : nsISupports {
   [noscript] voidStar CopyBinaryPref(in string pref, out long size);
   
   string CopyDefaultCharPref(in string pref);
+  wstring CopyDefaultUnicharPref(in string pref);
   [noscript] voidStar CopyDefaultBinaryPref(in string pref, out long size);
 
   nsIFileSpec GetFilePref(in string pref);
diff --git a/mozilla/modules/libpref/src/nsPref.cpp b/mozilla/modules/libpref/src/nsPref.cpp
index e048761b762..f6c6c8612ef 100644
--- a/mozilla/modules/libpref/src/nsPref.cpp
+++ b/mozilla/modules/libpref/src/nsPref.cpp
@@ -54,6 +54,7 @@
 #include "jsapi.h"
 
 #include "nsQuickSort.h"
+#include "nsXPIDLString.h"
 
 #ifdef _WIN32
 #include "windows.h"
@@ -114,6 +115,9 @@ protected:
     
     nsIFileSpec*                    mFileSpec;
     nsIFileSpec*                    mLIFileSpec;
+
+    static nsresult convertUTF8ToUnicode(const char *utf8String,
+                                         PRUnichar **aResult);
 }; // class nsPref
 
 nsPref* nsPref::gInstance = NULL;
@@ -655,6 +659,22 @@ NS_IMETHODIMP nsPref::SetDefaultCharPref(const char *pref,const char* value)
     return _convertRes(PREF_SetDefaultCharPref(pref, value));
 }
 
+NS_IMETHODIMP nsPref::SetDefaultUnicharPref(const char *pref,
+                                            const PRUnichar *value)
+{
+    nsresult rv;
+    nsAutoString str(value);
+
+    char *utf8String = str.ToNewUTF8String();
+
+    if (!utf8String) return NS_ERROR_OUT_OF_MEMORY;
+
+    rv = SetDefaultCharPref(pref, utf8String);
+    nsCRT::free(utf8String);
+
+    return NS_OK;
+}
+
 NS_IMETHODIMP nsPref::SetDefaultIntPref(const char *pref,PRInt32 value)
 {
     return _convertRes(PREF_SetDefaultIntPref(pref, value));
@@ -710,21 +730,27 @@ NS_IMETHODIMP nsPref::CopyUnicharPref(const char *pref, PRUnichar ** return_buf)
     nsresult rv;
     
     // get the UTF8 string for conversion
-    char *utf8String;
-    rv = CopyCharPref(pref, &utf8String);
+    nsXPIDLCString utf8String;
+    rv = CopyCharPref(pref, getter_Copies(utf8String));
     if (NS_FAILED(rv)) return rv;
-    
+
+    return convertUTF8ToUnicode(utf8String, return_buf);
+}
+
+nsresult
+nsPref::convertUTF8ToUnicode(const char *utf8String, PRUnichar ** aResult)
+{
+    NS_ENSURE_ARG_POINTER(aResult);
     // convert to PRUnichar using nsTextFormatter
     // this is so ugly, it allocates memory at least 4 times :(
     PRUnichar *unicodeString =
         nsTextFormatter::smprintf(unicodeFormatter, utf8String);
-    PL_strfree(utf8String);
     if (!unicodeString) return NS_ERROR_OUT_OF_MEMORY;
 
     // use the right allocator
-    *return_buf = nsCRT::strdup(unicodeString);
+    *aResult = nsCRT::strdup(unicodeString);
     nsTextFormatter::smprintf_free(unicodeString);
-    if (!*return_buf) return NS_ERROR_OUT_OF_MEMORY;
+    if (!*aResult) return NS_ERROR_OUT_OF_MEMORY;
 
     return NS_OK;
 }
@@ -741,6 +767,18 @@ NS_IMETHODIMP nsPref::CopyDefaultCharPref( const char *pref,
     return _convertRes(PREF_CopyDefaultCharPref(pref, return_buffer));
 }
 
+NS_IMETHODIMP nsPref::CopyDefaultUnicharPref( const char *pref,
+                                              PRUnichar ** return_buf)
+{
+    nsresult rv;
+    
+    nsXPIDLCString utf8String;
+    rv = CopyDefaultCharPref(pref, getter_Copies(utf8String));
+    if (NS_FAILED(rv)) return rv;
+    
+    return convertUTF8ToUnicode(utf8String, return_buf);
+}
+
 NS_IMETHODIMP nsPref::CopyDefaultBinaryPref(const char *pref, 
                             int * size, void ** return_val)
 {