From eaf56593d039ea4f4e91c133ec82a4c2f63f8a5b Mon Sep 17 00:00:00 2001
From: Przemyslaw Czerpak <druzus@priv.onet.pl>
Date: Mon, 13 Sep 2010 09:40:53 +0000
Subject: [PATCH] 2010-09-13 11:40 UTC+0200 Przemyslaw Czerpak
 (druzus/at/priv.onet.pl)   * harbour/src/rtl/hbzlib.c     + added new PRG
 function:          HB_GZCOMPRESSBOUND( <cData> | <nDataLen> ) ->
 <nMaxCompressLen>     ! fixed compilation with ZLIB versions earlier then
 1.2.0 broken by       missing deflateBound() function which I used recently.

---
 harbour/ChangeLog        |  7 +++++++
 harbour/src/rtl/hbzlib.c | 38 ++++++++++++++++++++++----------------
 2 files changed, 29 insertions(+), 16 deletions(-)

diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index aeee5d05fd..702a0facf2 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -16,6 +16,13 @@
    The license applies to all entries newer than 2009-04-28.
 */
 
+2010-09-13 11:40 UTC+0200 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
+  * harbour/src/rtl/hbzlib.c
+    + added new PRG function:
+         HB_GZCOMPRESSBOUND( <cData> | <nDataLen> ) -> <nMaxCompressLen>
+    ! fixed compilation with ZLIB versions earlier then 1.2.0 broken by
+      missing deflateBound() function which I used recently.
+
 2010-09-13 09:59 UTC+0200 Przemyslaw Czerpak (druzus/at/priv.onet.pl)
   * harbour/src/rtl/hbzlib.c
     ! added our own version of compressBound() function for
diff --git a/harbour/src/rtl/hbzlib.c b/harbour/src/rtl/hbzlib.c
index b8fe48696a..8160fe5fcf 100644
--- a/harbour/src/rtl/hbzlib.c
+++ b/harbour/src/rtl/hbzlib.c
@@ -57,8 +57,10 @@
 #include <zlib.h>
 
 /* Try to figure if we have this function. Z_RLE was introduced in 1.2.0.1,
-   while compressBound() was added in 1.2.0. This means we have to miss
-   compressBound() when using zlib 1.2.0. [vszakats] */
+   while compressBound() and deflateBound() were added in 1.2.0. This means
+   we have to miss compressBound() when using zlib 1.2.0. [vszakats] */
+/* ZLIB_VERNUM were added in version 1.2.0.2 so it cannot be used for older
+   zlib libraries */
 #if defined( Z_RLE )
    #define _HB_Z_COMPRESSBOUND
 #endif
@@ -68,6 +70,9 @@ static uLong hb_zlibCompressBound( uLong ulLen )
 {
    return ulLen + ( ulLen >> 12 ) + ( ulLen >> 14 ) + ( ulLen >> 25 ) + 13;
 }
+#define compressBound( n )    ( hb_zlibCompressBound( n )
+/* additional 12 bytes is for GZIP compression which uses bigger header */
+#define deflateBound( s, n )  ( hb_zlibCompressBound( n ) + 12 )
 #endif
 
 static HB_SIZE hb_zlibUncompressedSize( const char * szSrc, HB_SIZE nLen,
@@ -151,7 +156,7 @@ static int hb_gz_compress( char ** pDstPtr, HB_SIZE * pnDst,
    memset( &stream, 0, sizeof( z_stream ) );
    stream.next_in   = ( Bytef* ) pSrc;
    stream.avail_in  = ( uInt ) nSrc;
-   iResult = deflateInit2( &stream, level, Z_DEFLATED, 31, 8,
+   iResult = deflateInit2( &stream, level, Z_DEFLATED, 15 + 16, 8,
                            Z_DEFAULT_STRATEGY );
    if( iResult == Z_OK )
    {
@@ -209,17 +214,9 @@ HB_FUNC( HB_ZLIBVERSION )
 HB_FUNC( HB_ZCOMPRESSBOUND )
 {
    if( HB_ISCHAR( 1 ) )
-#if defined( _HB_Z_COMPRESSBOUND )
       hb_retnint( compressBound( ( uLong ) hb_parclen( 1 ) ) );
-#else
-      hb_retnint( hb_zlibCompressBound( ( uLong ) hb_parclen( 1 ) ) );
-#endif
    else if( HB_ISNUM( 1 ) )
-#if defined( _HB_Z_COMPRESSBOUND )
       hb_retnint( compressBound( ( uLong ) hb_parns( 1 ) ) );
-#else
-      hb_retnint( hb_zlibCompressBound( ( uLong ) hb_parns( 1 ) ) );
-#endif
    else
       hb_errRT_BASE_SubstR( EG_ARG, 3012, NULL, HB_ERR_FUNCNAME, HB_ERR_ARGS_BASEPARAMS );
 }
@@ -279,11 +276,7 @@ HB_FUNC( HB_ZCOMPRESS )
          else
          {
             ulDstLen = HB_ISNUM( 2 ) ? ( uLong ) hb_parns( 2 ) :
-#if defined( _HB_Z_COMPRESSBOUND )
-                                    compressBound( ( uLong ) nLen );
-#else
-                                    hb_zlibCompressBound( ( uLong ) nLen );
-#endif
+                                       compressBound( ( uLong ) nLen );
             pDest = ( char * ) hb_xalloc( ulDstLen + 1 );
          }
 
@@ -381,6 +374,19 @@ HB_FUNC( HB_ZUNCOMPRESS )
       hb_errRT_BASE_SubstR( EG_ARG, 3012, NULL, HB_ERR_FUNCNAME, HB_ERR_ARGS_BASEPARAMS );
 }
 
+/*
+ * HB_GZCOMPRESSBOUND( <cData> | <nDataLen> ) -> <nMaxCompressLen>
+ */
+HB_FUNC( HB_GZCOMPRESSBOUND )
+{
+   if( HB_ISCHAR( 1 ) )
+      hb_retnint( compressBound( ( uLong ) hb_parclen( 1 ) ) + 12 );
+   else if( HB_ISNUM( 1 ) )
+      hb_retnint( compressBound( ( uLong ) hb_parns( 1 ) ) + 12 );
+   else
+      hb_errRT_BASE_SubstR( EG_ARG, 3012, NULL, HB_ERR_FUNCNAME, HB_ERR_ARGS_BASEPARAMS );
+}
+
 /*
  * HB_GZCOMPRESS( <cData>, [<nDstBufLen>|<@cBuffer>], [<@nResult>], [<nLevel>] )
  *    => <cCompressedData> or NIL on Error