diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index d4ae0b707a..261aa55b8a 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -17,6 +17,33 @@
    past entries belonging to these authors: Viktor Szakats.
 */
 
+2009-05-15 12:36 UTC+0200 Viktor Szakats (harbour.01 syenar hu)
+  * utils/hbmk2/hbmk2.prg
+    % Changed default way of updating .po files. New method supports
+      incremental updates, thus much faster than previous solution.
+      As a side-effect, removed from source and changed translatable
+      strings won't automatically disappear from .po files.
+      This new method is also much friendlier to version control
+      systems, as .po entry order won't change on each minor update
+      (and generate a huge commit diff).
+    + Added -rebuildpo option to activate a complete rebuild of .po
+      files, clearing all no more existing entries. This operation
+      will take more time, will create big diffs and it's recommended
+      to be done when doing a complete rebuild (maybe this will
+      be automatically enforced later on).
+    ; With this, hbmk2 seems feature complete. (maybe C++/C mode
+      switching could be added yet, it's on the TODO list)
+
+  * bin/hb-func.sh
+    * Addition of libs= entry in hbmk.cfg file will now be
+      initiated by setting envvar HB_USER_LIBS_DEF (was HB_USER_LIBS),
+      to avoid potential binary build problems where locally
+      set HB_USER_LIBS envvar could create an unusuable (on other
+      systems) builds (hbmk2 setup).
+
+  + contrib/rddsql/readme.txt
+    + Added readme (posted on the list). Work of Mindaugas.
+
 2009-05-15 12:03 UTC+0200 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
   * harbour/contrib/rddads/ads1.c
     ! fixed typo in recent modification which caused that character fields
diff --git a/harbour/bin/hb-func.sh b/harbour/bin/hb-func.sh
index bd85a0fa44..711d025b05 100755
--- a/harbour/bin/hb-func.sh
+++ b/harbour/bin/hb-func.sh
@@ -252,8 +252,8 @@ mk_hbtools()
     if [ -n "${CC_HB_USER_LDFLAGS}" ]; then
         echo "ldflags=${CC_HB_USER_LDFLAGS}">> ${hb_hbmkcfg}
     fi
-    if [ -n "${HB_USER_LIBS}" ]; then
-        echo "libs=${HB_USER_LIBS}">> ${hb_hbmkcfg}
+    if [ -n "${HB_USER_LIBS_DEF}" ]; then
+        echo "libs=${HB_USER_LIBS_DEF}">> ${hb_hbmkcfg}
     fi
     if [ "${HB_GPM_MOUSE}" = "yes" ]; then
         echo "libs=gpm">> ${hb_hbmkcfg}
diff --git a/harbour/contrib/rddsql/readme.txt b/harbour/contrib/rddsql/readme.txt
new file mode 100644
index 0000000000..d91e1b5459
--- /dev/null
+++ b/harbour/contrib/rddsql/readme.txt
@@ -0,0 +1,133 @@
+/*
+ * $Id$
+ */
+
+                    Simple SQL Interface for Harbour
+
+
+
+1. Introduction
+
+   Simple SQL interface implements accessing SQL query result via RDD
+interface. It is not intended to be replacement for "transparent" move of
+DBFCDX application to SQL world.
+
+   I want to discuss this in more detail. Many current RDDs for SQL servers
+(ex. SQLRDD from xHarbour.com) tries to make a feeling you are working with
+DBF file, but not with SQL database. SQL server does not support many
+features, ex. RECNO(), deleted flag, file locks, record locks. These RDDs
+are emulating these features to make feeling of DBF. DELETED() function is
+emulated by creating additional table columns to store delete flag. Some
+"hidden system" tables are used to register locking operations and emulate
+record and file locks in DBF style. The idea of SQL query is also lost. If
+you do a simple loop
+
+ DBUSEAREA(, "select * from my_table")
+ DO WHILE ! EOF()
+   somefunc( FIELD->some_sql_field )
+   DBSKIP()
+ ENDDO
+
+RDD usualy will read SQL rows in portions, let's say 100 records per query.
+So, hidden queries are generated. If you are using indexes these queries
+are really complicated. Let's have index on FIELD1 + STR(FIELD2). A seek to
+value cValue1 + STR(nValue2) will generate a query like:
+
+ SELECT * FROM my_table
+     WHERE (FIELD1 == cValue1 and FIELD2 >= nValue2) or FIELD1 > cValue1
+     ORDER BY FIELD1, FIELD2, _RECNO
+     LIMIT 100
+
+After evaluation of first 100 cached records, next query will be generated:
+
+ SELECT * FROM my_table
+     WHERE (FIELD1 == cLastField1 and FIELD2 == nLastValue2 and _RECNO > nLastRecno) or
+           (FIELD1 == cLastField1 and FIELD2 > nLastValue2) or
+           FIELD1 > cLastValue1
+     ORDER BY FIELD1, FIELD2, _RECNO
+     LIMIT 100
+
+To optimize these queries the SQL index expresion should be
+"FIELD1,FIELD2,_RECNO", but not "FIELD1,FIELD2" as written in INDEX ON
+command.
+
+   "Simple SQL interface" is too long to repeat every time I want to
+address this library. I'll also use acronym "SSI" to address it.
+
+   The idea of SSI is different. It does not make hidden queries. All
+queries should be made explicitly by programmer. SSI gives access to query
+result via RDD interface, it does not tries to emulate DBF and be
+"plug-and-play" solution for DBF to SQL migration. If you do
+
+ DBUSEAREA(, "select * from my_table")
+
+all query (it could contain millions of records!) will be cached.
+
+   The features of SSI approach are:
+
+- It's possible to access SQL database of other applications. Other
+ applications usualy does not follow agreement of "plug-and-play" SQL drivers
+ about additional DELETED column, _RECNO in the end of index expression, etc.
+ Access of SQL database of other applications is sometimes not possible.
+
+- It's query oriented. That means a simple DO WHILE ! EOF() loop will iterate
+ each records once and only once. This is not true for "plug-and-play" SQL
+ drivers, if indexing is used. Just like in the case of loop over DBF file.
+ It is not guaranteed that all records are included! Yes! If key value of the
+ first record in index is changed to be the last record in index during the
+ phase of record processing, DO WHILE ! EOF() loop will iterate only this
+ single records even if the database contains millions of records. Your sould
+ do FLOCK() on DBF to guarantee the records are not changed. Do you use FLOCK()
+ before readonly DO WHILE ! EOF() loops? :)
+
+
+
+2. Architecture
+
+
+             +-------------+
+             |             |
+             | SQLMIX RDD  |
+             |             |
+             +-------------+
+                  |  ^
+                  V  |
+             +-------------+    +---------+
+             |             |--->|         |
+             | SQLBASE RDD |    |   SDD   |
+             |             |<---|         |
+             +-------------+    +---------+
+
+
+   SQLBASE RDD implements basic functionality for accessing SQL query result
+via RDD interface. This RDD could be used, if indexing of query result is not
+necessary or all indexing is done by SQL server (by using ORDER BY clause).
+
+   SQLMIX RDD implements indexing of query result. This indexing is not
+related to SQL server ORDER BY clause. SQLMIX do indexing of the query on the
+client side.
+
+   SDD is acronym for Sql Database Driver. RDD is used to implement access
+of different database formats like DBF, SDF, etc. SDD is used to implement
+access of different SQL databases. Every SQL server (MySQL, PostgreSQL, etc.)
+has a corresponding SDD. SDD driver implements a specific part of data
+exchange interface between SQLBASE and SQL server.
+
+   A few additional functions are also implemented, ex. HB_SQLCONNECT().
+Usualy these functions are just a shorter version of corresponding RDDINFO()
+call.
+
+
+
+3. Modifying database
+
+   SSI presents a query result via RDD interface and generates no hidden
+SQL queries. So, how database can be changed? Does DBAPPEND() and FIELDPUT()
+works, or is it readonly SQL interface?
+   DBAPPEND(), FIELDPUT() and other similiar functions work on cached query
+result, i.e. query can be appended by new rows and field values can be
+changed, but SQL database is not changed. DBCREATE() function can also be
+used to create an "empty query result" but no table is created on SQL server.
+So, SSI can also be used as implementation of "array RDD".
+   The programmer must call SQL command explicitly to modify SQL tables.
+SSI provides a method to detect which cached rows was changed or appended.
diff --git a/harbour/utils/hbmk2/hbmk2.prg b/harbour/utils/hbmk2/hbmk2.prg
index 00b6f31b23..b9ad83318f 100644
--- a/harbour/utils/hbmk2/hbmk2.prg
+++ b/harbour/utils/hbmk2/hbmk2.prg
@@ -35,7 +35,7 @@
  *    bash script with similar purpose for gcc family.
  *    entry point override method and detection code for gcc.
  *    rtlink/blinker link script parsers.
- *    POTMerge(), LoadPOTFiles(), LoadPOTFilesAsHash(), GenHbl() and AutoTrans().
+ *    POTMerge(), LoadPOTFilesAsHash(), GenHbl() and AutoTrans().
  *       (with local modifications by hbmk author)
  *
  * See COPYING for licensing terms.
@@ -95,7 +95,6 @@
 /* TODO: Further clean hbmk context var usage (hbmk2 scope, project scope,
          adding rest of variables). */
 /* TODO: Finish C++/C mode selection. */
-/* TODO: Incremental .pot to .po merge. */
 /* TODO: Add a way to fallback to stop if required headers couldn't be found.
          This needs a way to spec what key headers to look for. */
 
@@ -183,21 +182,22 @@ REQUEST hbmk_KEYW
 #define _HBMK_nCOMPR            37
 #define _HBMK_lRUN              38
 #define _HBMK_lINC              39
+#define _HBMK_lREBUILDPO        40
 
-#define _HBMK_aPO               40
-#define _HBMK_cHBL              41
-#define _HBMK_aLNG              42
-#define _HBMK_cPO               43
+#define _HBMK_aPO               41
+#define _HBMK_cHBL              42
+#define _HBMK_aLNG              43
+#define _HBMK_cPO               44
 
-#define _HBMK_lDEBUGTIME        44
-#define _HBMK_lDEBUGINC         45
-#define _HBMK_lDEBUGSTUB        46
-#define _HBMK_lDEBUGI18N        47
+#define _HBMK_lDEBUGTIME        45
+#define _HBMK_lDEBUGINC         46
+#define _HBMK_lDEBUGSTUB        47
+#define _HBMK_lDEBUGI18N        48
 
-#define _HBMK_cCCPATH           48
-#define _HBMK_cCCPREFIX         49
+#define _HBMK_cCCPATH           49
+#define _HBMK_cCCPREFIX         50
 
-#define _HBMK_MAX_              49
+#define _HBMK_MAX_              50
 
 PROCEDURE Main( ... )
    LOCAL aArgs := hb_AParams()
@@ -445,6 +445,7 @@ FUNCTION hbmk( aArgs )
    hbmk[ _HBMK_nCOMPR ] := _COMPR_OFF
    hbmk[ _HBMK_lRUN ] := .F.
    hbmk[ _HBMK_lINC ] := .F.
+   hbmk[ _HBMK_lREBUILDPO ] := .F.
 
    hbmk[ _HBMK_lDEBUGTIME ] := .F.
    hbmk[ _HBMK_lDEBUGINC ] := .F.
@@ -1099,6 +1100,7 @@ FUNCTION hbmk( aArgs )
       CASE cParamL == "-beep-" .OR. ;
            cParamL == "-nobeep"          ; s_lBEEP      := .F.
       CASE cParamL == "-rebuild"         ; hbmk[ _HBMK_lINC ]       := .T. ; hbmk[ _HBMK_lREBUILD ] := .T.
+      CASE cParamL == "-rebuildpo"       ; hbmk[ _HBMK_lREBUILDPO ] := .T.
       CASE cParamL == "-clean"           ; hbmk[ _HBMK_lINC ]       := .T. ; s_lCLEAN := .T.
       CASE cParamL == "-inc"             ; hbmk[ _HBMK_lINC ]       := .T.
       CASE cParamL == "-inc-" .OR. ;
@@ -2873,8 +2875,14 @@ FUNCTION hbmk( aArgs )
          s_aRESSRC_TODO := s_aRESSRC
       ENDIF
 
-      IF ! Empty( hbmk[ _HBMK_cPO ] ) .AND. ! Empty( s_aPRG ) .AND. Len( s_aPRG_TODO ) > 0
-         MakePO( hbmk, ListDirExt( s_aPRG, cWorkDir, ".pot" ) )
+      IF hbmk[ _HBMK_lREBUILDPO ]
+         IF ! Empty( hbmk[ _HBMK_cPO ] ) .AND. ! Empty( s_aPRG )
+            RebuildPO( hbmk, ListDirExt( s_aPRG, cWorkDir, ".pot" ) )
+         ENDIF
+      ELSE
+         IF ! Empty( hbmk[ _HBMK_cPO ] ) .AND. Len( s_aPRG_TODO ) > 0
+            UpdatePO( hbmk, ListDirExt( s_aPRG_TODO, cWorkDir, ".pot" ) )
+         ENDIF
       ENDIF
 
       IF Len( hbmk[ _HBMK_aPO ] ) > 0 .AND. hbmk[ _HBMK_cHBL ] != NIL .AND. ! s_lCLEAN
@@ -5081,9 +5089,9 @@ STATIC FUNCTION rtlnk_process( hbmk, cCommands, cFileOut, aFileList, aLibList, ;
 
    RETURN .T.
 
-/* .hbl generation */
+/* .po generation */
 
-STATIC PROCEDURE MakePO( hbmk, aPOTIN )
+STATIC PROCEDURE RebuildPO( hbmk, aPOTIN )
    LOCAL cLNG
    LOCAL fhnd
    LOCAL cPOTemp
@@ -5098,10 +5106,10 @@ STATIC PROCEDURE MakePO( hbmk, aPOTIN )
          IF fhnd != F_ERROR
             FClose( fhnd )
             IF hbmk[ _HBMK_lDEBUGI18N ]
-               hbmk_OutStd( hb_StrFormat( "MakePO: file .pot list: %1$s", ArrayToList( aPOTIN, ", " ) ) )
-               hbmk_OutStd( hb_StrFormat( "MakePO: temp unified .po: %1$s", cPOTemp ) )
+               hbmk_OutStd( hb_StrFormat( "RebuildPO: file .pot list: %1$s", ArrayToList( aPOTIN, ", " ) ) )
+               hbmk_OutStd( hb_StrFormat( "RebuildPO: temp unified .po: %1$s", cPOTemp ) )
             ENDIF
-            POTMerge( hbmk, aPOTIN, cPOTemp )
+            POTMerge( hbmk, aPOTIN, NIL, cPOTemp )
          ELSE
             hbmk_OutStd( I_( "Error: Cannot create temporary unified .po file." ) )
          ENDIF
@@ -5109,13 +5117,13 @@ STATIC PROCEDURE MakePO( hbmk, aPOTIN )
       cPOCooked := StrTran( hbmk[ _HBMK_cPO ], _LNG_MARKER, cLNG )
       IF hb_FileExists( cPOCooked )
          IF hbmk[ _HBMK_lDEBUGI18N ]
-            hbmk_OutStd( hb_StrFormat( "MakePO: updating unified .po: %1$s", cPOCooked ) )
+            hbmk_OutStd( hb_StrFormat( "RebuildPO: updating unified .po: %1$s", cPOCooked ) )
          ENDIF
          AutoTrans( hbmk, cPOTemp, { cPOCooked }, cPOCooked )
          AAdd( aUpd, cLNG )
       ELSE
          IF hbmk[ _HBMK_lDEBUGI18N ]
-            hbmk_OutStd( hb_StrFormat( "MakePO: creating unified .po: %1$s", cPOCooked ) )
+            hbmk_OutStd( hb_StrFormat( "RebuildPO: creating unified .po: %1$s", cPOCooked ) )
          ENDIF
          hb_FCopy( cPOTemp, cPOCooked )
          AAdd( aNew, cLNG )
@@ -5135,14 +5143,36 @@ STATIC PROCEDURE MakePO( hbmk, aPOTIN )
    ENDIF
    IF ! Empty( aUpd )
       IF Empty( hbmk[ _HBMK_aLNG ] )
-         hbmk_OutStd( hb_StrFormat( I_( "Updated .po file '%1$s'" ), hbmk[ _HBMK_cPO ] ) )
+         hbmk_OutStd( hb_StrFormat( I_( "Rebuilt .po file '%1$s'" ), hbmk[ _HBMK_cPO ] ) )
       ELSE
-         hbmk_OutStd( hb_StrFormat( I_( "Updated .po file '%1$s' for language(s): %2$s" ), hbmk[ _HBMK_cPO ], ArrayToList( aUpd, "," ) ) )
+         hbmk_OutStd( hb_StrFormat( I_( "Rebuilt .po file '%1$s' for language(s): %2$s" ), hbmk[ _HBMK_cPO ], ArrayToList( aUpd, "," ) ) )
       ENDIF
    ENDIF
 
    RETURN
 
+/* .po update */
+
+STATIC PROCEDURE UpdatePO( hbmk, aPOTIN )
+   LOCAL cLNG
+
+   LOCAL aUpd := {}
+
+   FOR EACH cLNG IN iif( Empty( hbmk[ _HBMK_aLNG ] ) .OR. !( _LNG_MARKER $ hbmk[ _HBMK_cPO ] ), { _LNG_MARKER }, hbmk[ _HBMK_aLNG ] )
+      POTMerge( hbmk, aPOTIN, StrTran( hbmk[ _HBMK_cPO ], _LNG_MARKER, cLNG ), StrTran( hbmk[ _HBMK_cPO ], _LNG_MARKER, cLNG ) )
+      AAdd( aUpd, cLNG )
+   NEXT
+
+   IF Empty( hbmk[ _HBMK_aLNG ] )
+      hbmk_OutStd( hb_StrFormat( I_( "Updated .po file '%1$s'" ), hbmk[ _HBMK_cPO ] ) )
+   ELSE
+      hbmk_OutStd( hb_StrFormat( I_( "Updated .po file '%1$s' for language(s): %2$s" ), hbmk[ _HBMK_cPO ], ArrayToList( aUpd, "," ) ) )
+   ENDIF
+
+   RETURN
+
+/* .hbl generation */
+
 STATIC PROCEDURE MakeHBL( hbmk, cHBL )
    LOCAL cPO
    LOCAL tPO
@@ -5192,12 +5222,20 @@ STATIC PROCEDURE MakeHBL( hbmk, cHBL )
 
    RETURN
 
-STATIC FUNCTION LoadPOTFiles( hbmk, aFiles, lIgnoreError )
-   LOCAL aTrans := {}, aTrans2
+STATIC FUNCTION LoadPOTFiles( hbmk, aFiles, cFileBase, lIgnoreError )
+   LOCAL aTrans, aTrans2
    LOCAL hIndex
    LOCAL cErrorMsg
    LOCAL cFileName
 
+   IF ! Empty( cFileBase )
+      aTrans := __i18n_potArrayLoad( cFileBase, @cErrorMsg )
+   ENDIF
+
+   IF aTrans == NIL
+      aTrans := {}
+   ENDIF
+
    FOR EACH cFileName IN aFiles
       aTrans2 := __i18n_potArrayLoad( cFileName, @cErrorMsg )
       IF aTrans2 != NIL
@@ -5237,9 +5275,9 @@ STATIC FUNCTION LoadPOTFilesAsHash( hbmk, aFiles )
 
    RETURN hTrans
 
-STATIC PROCEDURE POTMerge( hbmk, aFiles, cFileOut )
+STATIC PROCEDURE POTMerge( hbmk, aFiles, cFileBase, cFileOut )
    LOCAL cErrorMsg
-   LOCAL aTrans := LoadPOTFiles( hbmk, aFiles, .T. )
+   LOCAL aTrans := LoadPOTFiles( hbmk, aFiles, cFileBase, .T. )
 
    IF aTrans != NIL
       IF !__i18n_potArraySave( cFileOut, aTrans, @cErrorMsg )
@@ -5253,7 +5291,7 @@ STATIC PROCEDURE AutoTrans( hbmk, cFileIn, aFiles, cFileOut )
    LOCAL cErrorMsg
 
    IF !__I18N_potArraySave( cFileOut, ;
-         __I18N_potArrayTrans( LoadPOTFiles( hbmk, { cFileIn }, .F. ), ;
+         __I18N_potArrayTrans( LoadPOTFiles( hbmk, {}, cFileIn, .F. ), ;
                                LoadPOTFilesAsHash( hbmk, aFiles ) ), @cErrorMsg )
       hbmk_OutErr( hb_StrFormat( I_( "Error: %1$s" ), cErrorMsg ) )
    ENDIF
@@ -5567,6 +5605,7 @@ STATIC PROCEDURE ShowHelp( lLong )
       { "-hbl[=<output>]"   , I_( "output .hbl filename. ${lng} macro is accepted in filename" ) },;
       { "-lng=<languages>"  , I_( "list of languages to be replaced in ${lng} macros in .pot/.po filenames and output .hbl/.po filenames. Comma separared list:\n-lng=en-EN,hu-HU,de" ) },;
       { "-po=<output>"      , I_( "create/update .po file from source. Merge it with previous .po file of the same name" ) },;
+      { "-rebuildpo"        , I_( "recreate .po file, thus removing all obsolete entries in it" ) },;
       NIL,;
       { "-hbrun"            , I_( "run target" ) },;
       { "-hbcmp|-clipper"   , I_( "stop after creating the object files\ncreate link/copy hbmk to hbcmp/clipper for the same effect" ) },;