diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 39e650b4e8..85a83ff5ff 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -17,6 +17,29 @@
    past entries belonging to author(s): Viktor Szakats.
 */
 
+2009-12-11 20:42 UTC+0100 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
+  * harbour/src/vm/strapi.c
+  * harbour/include/hbapistr.h
+    + added new functions to operate on Harbour wide character strings:
+         ULONG hb_wstrlen( const HB_WCHAR * szText );
+         HB_WCHAR * hb_wstrdup( const HB_WCHAR * szText );
+         HB_WCHAR * hb_wstrndup( const HB_WCHAR * szText, ULONG ulLen );
+         int hb_wstrcmp( const HB_WCHAR * s1, const HB_WCHAR * s2 );
+         int hb_wstrncmp( const HB_WCHAR * s1,
+                          const HB_WCHAR * s2, ULONG count );
+    + added new functions to convert NULL pointers to empty strings:
+         const char * hb_strnull( const char * str );
+         const HB_WCHAR * hb_wstrnull( const HB_WCHAR * str );
+    + added new functions to convert string buffer returned by Harbour
+      string functions to writable state:
+         char * hb_strunshare( void ** phStr,
+                               const char * pStr, ULONG ulLen );
+         HB_WCHAR * hb_wstrunshare( void ** phStr,
+                                    const HB_WCHAR * pStr, ULONG ulLen );
+  * harbour/include/hbwinuni.h
+    ! fixed HB_PARSTRDEF() to return empty string instead of NULL
+    ! fixed HB_ARRAYSETSTR() to accept NULL as string parameter
+
 2009-12-11 20:25 UTC+0100 Viktor Szakats (harbour.01 syenar.hu)
   * contrib/hbwin/win_regc.c
     ! WIN_REGSETVALUEEX(): Off by one bug fixed in prev commit.
diff --git a/harbour/include/hbapistr.h b/harbour/include/hbapistr.h
index 5ef8a9d431..93ac914771 100644
--- a/harbour/include/hbapistr.h
+++ b/harbour/include/hbapistr.h
@@ -58,6 +58,18 @@
 
 HB_EXTERN_BEGIN
 
+extern HB_EXPORT ULONG hb_wstrlen( const HB_WCHAR * szText );
+extern HB_EXPORT int hb_wstrcmp( const HB_WCHAR * s1, const HB_WCHAR * s2 );
+extern HB_EXPORT int hb_wstrncmp( const HB_WCHAR * s1, const HB_WCHAR * s2, ULONG count );
+extern HB_EXPORT HB_WCHAR * hb_wstrdup( const HB_WCHAR * szText );
+extern HB_EXPORT HB_WCHAR * hb_wstrndup( const HB_WCHAR * szText, ULONG ulLen );
+
+extern HB_EXPORT char * hb_strunshare( void ** phStr, const char * pStr, ULONG ulLen );
+extern HB_EXPORT HB_WCHAR * hb_wstrunshare( void ** phStr, const HB_WCHAR * pStr, ULONG ulLen );
+extern HB_EXPORT const char * hb_strnull( const char * str );
+extern HB_EXPORT const HB_WCHAR * hb_wstrnull( const HB_WCHAR * str );
+
+
 extern HB_EXPORT void hb_strfree( void * hString );
 
 extern HB_EXPORT const char * hb_itemGetStr( PHB_ITEM pItem, void * cdp, void ** phString, ULONG * pulLen );
diff --git a/harbour/include/hbwinuni.h b/harbour/include/hbwinuni.h
index 0774e03d93..983b26db6a 100644
--- a/harbour/include/hbwinuni.h
+++ b/harbour/include/hbwinuni.h
@@ -61,27 +61,27 @@
 
 #if defined( UNICODE )
    #define HB_PARSTR( n, h, len )       hb_parstr_u16( n, HB_CDP_ENDIAN_NATIVE, h, len )
-   #define HB_PARSTRDEF( n, h, len )    hb_parstr_u16( n, HB_CDP_ENDIAN_NATIVE, h, len )
+   #define HB_PARSTRDEF( n, h, len )    hb_wstrnull( hb_parstr_u16( n, HB_CDP_ENDIAN_NATIVE, h, len ) )
    #define HB_RETSTR( str )             hb_retstr_u16( HB_CDP_ENDIAN_NATIVE, ( const HB_WCHAR * ) ( str ) )
    #define HB_RETSTRLEN( str, len )     hb_retstrlen_u16( HB_CDP_ENDIAN_NATIVE, ( const HB_WCHAR * ) ( str ), len )
    #define HB_STORSTR( str, n )         hb_storstr_u16( HB_CDP_ENDIAN_NATIVE, ( const HB_WCHAR * ) ( str ), n )
    #define HB_STORSTRLEN( str, len, n ) hb_storstrlen_u16( HB_CDP_ENDIAN_NATIVE, ( const HB_WCHAR * ) ( str ), len, n )
    #define HB_ARRAYSETSTR( arr, n, str ) \
       hb_itemPutStrLenU16( hb_arrayGetItemPtr( arr, n ), \
-                           HB_CDP_ENDIAN_NATIVE, str, lstrlenW( str ) )
+                           HB_CDP_ENDIAN_NATIVE, str, hb_wstrlen( hb_wstrnull( str ) ) )
    #define HB_ARRAYSETSTRLEN( arr, n, str, len ) \
       hb_itemPutStrLenU16( hb_arrayGetItemPtr( arr, n ), \
                            HB_CDP_ENDIAN_NATIVE, str, len )
 #else
    #define HB_PARSTR( n, h, len )       hb_parstr( n, hb_setGetOSCP(), h, len )
-   #define HB_PARSTRDEF( n, h, len )    hb_parstr( n, hb_setGetOSCP(), h, len )
+   #define HB_PARSTRDEF( n, h, len )    hb_strnull( hb_parstr( n, hb_setGetOSCP(), h, len ) )
    #define HB_RETSTR( str )             hb_retstr( hb_setGetOSCP(), str )
    #define HB_RETSTRLEN( str, len )     hb_retstrlen( hb_setGetOSCP(), str, len )
    #define HB_STORSTR( str, n )         hb_storstr( hb_setGetOSCP(), str, n )
    #define HB_STORSTRLEN( str, len, n ) hb_storstrlen( hb_setGetOSCP(), str, len, n )
    #define HB_ARRAYSETSTR( arr, n, str ) \
       hb_itemPutStrLen( hb_arrayGetItemPtr( arr, n ), \
-                        hb_setGetOSCP(), str, strlen( str ) )
+                        hb_setGetOSCP(), str, strlen( hb_strnull( str ) ) )
    #define HB_ARRAYSETSTRLEN( arr, n, str, len ) \
       hb_itemPutStrLen( hb_arrayGetItemPtr( arr, n ), \
                         hb_setGetOSCP(), str, len )
diff --git a/harbour/src/vm/strapi.c b/harbour/src/vm/strapi.c
index febe6876b0..45cf73b154 100644
--- a/harbour/src/vm/strapi.c
+++ b/harbour/src/vm/strapi.c
@@ -58,10 +58,12 @@
 
 static const HB_WCHAR s_szConstStr[ 1 ] = { 0 };
 
-static ULONG hb_wstrlen( const HB_WCHAR * szText )
+ULONG hb_wstrlen( const HB_WCHAR * szText )
 {
    ULONG ulLen = 0;
 
+   HB_TRACE(HB_TR_DEBUG, ("hb_wstrlen(%p)", szText));
+
    if( szText )
    {
       while( szText[ ulLen ] )
@@ -71,6 +73,140 @@ static ULONG hb_wstrlen( const HB_WCHAR * szText )
    return ulLen;
 }
 
+int hb_wstrcmp( const HB_WCHAR * s1, const HB_WCHAR * s2 )
+{
+   int rc = 0;
+
+   HB_TRACE(HB_TR_DEBUG, ("hb_wstrcmp(%p, %p)", s1, s2));
+
+   for( ;; )
+   {
+      if( *s1 != *s2 )
+      {
+         rc = ( *s1 < *s2 ? -1 : 1 );
+         break;
+      }
+      else if( *s1 == 0 )
+         break;
+
+      s1++;
+      s2++;
+   }
+
+   return rc;
+}
+
+int hb_wstrncmp( const HB_WCHAR * s1, const HB_WCHAR * s2, ULONG count )
+{
+   int rc = 0;
+
+   HB_TRACE(HB_TR_DEBUG, ("hb_wstrncmp(%p, %p, %lu)", s1, s2, count));
+
+   while( count-- )
+   {
+      if( *s1 != *s2 )
+      {
+         rc = ( *s1 < *s2 ? -1 : 1 );
+         break;
+      }
+      else if( *s1 == 0 )
+         break;
+
+      s1++;
+      s2++;
+   }
+
+   return rc;
+}
+
+HB_WCHAR * hb_wstrdup( const HB_WCHAR * szText )
+{
+   HB_WCHAR * pszDest;
+   ULONG ulSize;
+
+   HB_TRACE(HB_TR_DEBUG, ("hb_wstrdup(%p)", szText));
+
+   ulSize = ( hb_wstrlen( szText ) + 1 ) * sizeof( HB_WCHAR );
+   pszDest = ( HB_WCHAR * ) hb_xgrab( ulSize );
+
+   memcpy( pszDest, szText, ulSize );
+
+   return pszDest;
+}
+
+HB_WCHAR * hb_wstrndup( const HB_WCHAR * szText, ULONG ulLen )
+{
+   HB_WCHAR * pszDest;
+   ULONG ulSize;
+
+   HB_TRACE(HB_TR_DEBUG, ("hb_wstrndup(%p,%lu)", szText,ulLen));
+
+   ulSize = hb_wstrlen( szText );
+   if( ulSize < ulLen )
+      ulLen = ulSize;
+   ulSize = ulLen * sizeof( HB_WCHAR );
+   pszDest = ( HB_WCHAR * ) hb_xgrab( ulSize + sizeof( HB_WCHAR ) );
+   memcpy( pszDest, szText, ulSize );
+   pszDest[ ulLen ] = 0;
+
+   return pszDest;
+}
+
+HB_WCHAR * hb_wstrunshare( void ** phStr, const HB_WCHAR * pStr, ULONG ulLen )
+{
+   HB_TRACE(HB_TR_DEBUG, ("hb_wstrunshare(%p,%p,%lu)", phStr, pStr, ulLen));
+
+   if( pStr == NULL || phStr == NULL || *phStr == NULL )
+      return NULL;
+
+   if( *phStr == ( void * ) s_szConstStr && ulLen > 0 )
+   {
+      HB_WCHAR * pszDest = ( HB_WCHAR * ) hb_xgrab( ( ulLen + 1 ) *
+                                                    sizeof( HB_WCHAR ) );
+      memcpy( pszDest, pStr, ulLen * sizeof( HB_WCHAR ) );
+      pszDest[ ulLen ] = 0;
+      * phStr = ( void * ) pszDest;
+
+      return pszDest;
+   }
+
+   return ( HB_WCHAR * ) pStr;
+}
+
+char * hb_strunshare( void ** phStr, const char * pStr, ULONG ulLen )
+{
+   HB_TRACE(HB_TR_DEBUG, ("hb_strunshare(%p,%p,%lu)", phStr, pStr, ulLen));
+
+   if( pStr == NULL || phStr == NULL || *phStr == NULL )
+      return NULL;
+
+   if( *phStr == ( void * ) s_szConstStr && ulLen > 0 )
+   {
+      char * pszDest = ( char * ) hb_xgrab( ( ulLen + 1 ) * sizeof( char ) );
+      memcpy( pszDest, pStr, ulLen * sizeof( char ) );
+      pszDest[ ulLen ] = 0;
+      * phStr = ( void * ) pszDest;
+
+      return pszDest;
+   }
+
+   return ( char * ) pStr;
+}
+
+const char * hb_strnull( const char * str )
+{
+   HB_TRACE(HB_TR_DEBUG, ("hb_strnull(%p)", str));
+
+   return str ? str : "";
+}
+
+const HB_WCHAR * hb_wstrnull( const HB_WCHAR * str )
+{
+   HB_TRACE(HB_TR_DEBUG, ("hb_wstrnull(%p)", str));
+
+   return str ? str : s_szConstStr;
+}
+
 void hb_strfree( void * hString )
 {
    HB_TRACE(HB_TR_DEBUG, ("hb_strfree(%p)", hString));