diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 227ce47ba9..d61a3cc818 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -16,6 +16,34 @@
    The license applies to all entries newer than 2009-04-28.
 */
 
+2012-02-17 21:04 UTC+0100 Przemyslaw Czerpak (druzus/at/poczta.onet.pl)
+  * harbour/include/hbcom.ch
+  * harbour/src/rtl/hbcom.c
+    + added new serial error code: HB_COM_ERR_PIPE
+      It's usable for some devices which use EPIPE error to
+      signal disconnected state.
+
+  * harbour/src/3rd/zlib/zlib.h
+    + added missing declarations for exported public functions
+
+  * harbour/src/3rd/zlib/gzlib.c
+  * harbour/src/3rd/zlib/gzguts.h
+    ! fixed POCC and XCC compilation
+    * enabled support for vsnprintf() in OpenWatcom builds
+
+  * harbour/src/3rd/zlib/Makefile
+    ! fixed all non windows and WATCOM builds - critical macro
+      set by ./configure in ZLIB was not defined
+    ; warning long file support is broken on most of 32bit platforms
+      so be careful with GZIP functions.
+
+  * harbour/contrib/gtwvg/gtwvg.h
+    + define WINVER 0x0500 - it's necessary for some macros and
+      structures used by GTWVG code
+
+  * harbour/contrib/gtwvg/wvgwin.c
+    * removed redundant line with 'break;' instruction
+
 2012-02-17 16:32 UTC+0100 Viktor Szakats (harbour syenar.net)
   * package/winuni/mpkg_win_uni.bat
   * INSTALL
diff --git a/harbour/contrib/gtwvg/gtwvg.h b/harbour/contrib/gtwvg/gtwvg.h
index 09cf0acf7f..dc6966f0f5 100644
--- a/harbour/contrib/gtwvg/gtwvg.h
+++ b/harbour/contrib/gtwvg/gtwvg.h
@@ -62,7 +62,10 @@
    #ifndef __MINGW64_VERSION_MAJOR
       #define _WIN32_IE 0x0500
    #endif
-#endif
+#endif /* _WIN32_IE */
+#ifndef WINVER
+   #define WINVER 0x0500
+#endif /* WINVER */
 
 #include "hbset.h"
 #include "hbgtcore.h"
diff --git a/harbour/contrib/gtwvg/wvgwin.c b/harbour/contrib/gtwvg/wvgwin.c
index d7ebb0fd4c..a097de4284 100644
--- a/harbour/contrib/gtwvg/wvgwin.c
+++ b/harbour/contrib/gtwvg/wvgwin.c
@@ -1618,7 +1618,6 @@ HB_FUNC( WVG_SENDCBMESSAGE )
    case CB_SETTOPINDEX            : // An application sends the CB_SETTOPINDEX message to ensure that a particular item is visible in the list box of a combo box. The system scrolls the list box contents so that either the specified item appears at the top of the list box or the maximum scroll range has been reached.
       hb_retl( SendMessage( hCB, CB_SETTOPINDEX, hb_parni( 3 ), 0 ) ? FALSE : TRUE );
       break;
-      break;
    case CB_SHOWDROPDOWN           : // An application sends a CB_SHOWDROPDOWN message to show or hide the list box of a combo box that has the CBS_DROPDOWN or CBS_DROPDOWNLIST style.
       SendMessage( hCB, CB_SHOWDROPDOWN, hb_parl( 3 ), 0 );
       break;
diff --git a/harbour/include/hbcom.ch b/harbour/include/hbcom.ch
index d52c23e2e2..d3318968bb 100644
--- a/harbour/include/hbcom.ch
+++ b/harbour/include/hbcom.ch
@@ -126,5 +126,6 @@
 #define HB_COM_ERR_OTHER            7
 #define HB_COM_ERR_ALREADYOPEN      8
 #define HB_COM_ERR_IO               9
+#define HB_COM_ERR_PIPE             10
 
 #endif /* HB_COM_CH_ */
diff --git a/harbour/src/3rd/zlib/Makefile b/harbour/src/3rd/zlib/Makefile
index 01485face3..14163a970b 100644
--- a/harbour/src/3rd/zlib/Makefile
+++ b/harbour/src/3rd/zlib/Makefile
@@ -42,6 +42,13 @@ ifneq ($(HB_HAS_ZLIB_LOCAL),)
          HB_CFLAGS += -DNO_VIZ
       endif
    endif
+   ifeq ($(filter $(HB_PLATFORM),win wce),)
+      HB_CFLAGS += -DHAVE_UNISTD_H
+   else
+      ifneq ($(filter $(HB_COMPILER),watcom),)
+         HB_CFLAGS += -DHAVE_UNISTD_H
+      endif
+   endif
    include $(TOP)$(ROOT)config/lib.mk
 else
    HB_SKIP_REASON := unused
diff --git a/harbour/src/3rd/zlib/gzguts.h b/harbour/src/3rd/zlib/gzguts.h
index 3107c363b2..90b82286df 100644
--- a/harbour/src/3rd/zlib/gzguts.h
+++ b/harbour/src/3rd/zlib/gzguts.h
@@ -27,7 +27,7 @@
 #endif
 #include <fcntl.h>
 
-#ifdef __TURBOC__
+#if defined(__TURBOC__) || defined(__XCC__) || defined(__POCC__)
 #  include <io.h>
 #endif
 
@@ -35,7 +35,8 @@
 #  define NO_GZCOMPRESS
 #endif
 
-#if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550)
+#if defined(STDC99) || (defined(__TURBOC__) && __TURBOC__ >= 0x550) || \
+    defined(__WATCOMC__)
 #  ifndef HAVE_VSNPRINTF
 #    define HAVE_VSNPRINTF
 #  endif
diff --git a/harbour/src/3rd/zlib/gzlib.c b/harbour/src/3rd/zlib/gzlib.c
index 7aedab8e2d..62eebf83e3 100644
--- a/harbour/src/3rd/zlib/gzlib.c
+++ b/harbour/src/3rd/zlib/gzlib.c
@@ -5,7 +5,11 @@
 
 #include "gzguts.h"
 
-#if defined(_WIN32) && !defined(__BORLANDC__)
+#if defined(__XCC__)
+#  define LSEEK lseek
+#elif defined(__POCC__)
+#  define LSEEK _lseek64
+#elif defined(_WIN32) && !defined(__BORLANDC__)
 #  define LSEEK _lseeki64
 #else
 #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
diff --git a/harbour/src/3rd/zlib/zlib.h b/harbour/src/3rd/zlib/zlib.h
index 79142d1172..c5e7ee22b8 100644
--- a/harbour/src/3rd/zlib/zlib.h
+++ b/harbour/src/3rd/zlib/zlib.h
@@ -1700,6 +1700,8 @@ ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));
    ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
    ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
    ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
+   ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
+   ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
 #endif
 
 #else /* Z_SOLO */
diff --git a/harbour/src/rtl/hbcom.c b/harbour/src/rtl/hbcom.c
index cf3aa0bd81..0a4eee05f8 100644
--- a/harbour/src/rtl/hbcom.c
+++ b/harbour/src/rtl/hbcom.c
@@ -312,6 +312,9 @@ static void hb_comSetOsError( PHB_COM pCom, HB_BOOL fError )
       case EIO:
          pCom->error = HB_COM_ERR_IO;
          break;
+      case EPIPE:
+         pCom->error = HB_COM_ERR_PIPE;
+         break;
       case EBUSY:
          pCom->error = HB_COM_ERR_BUSY;
          break;