From bfe41a49e2afbb70314835d0ee6fd81f973bd1df Mon Sep 17 00:00:00 2001
From: daniel <daniel@freepascal.org>
Date: Sat, 9 Sep 2006 10:02:57 +0000
Subject: [PATCH]   + FPC supports pointer arithmetic.

git-svn-id: trunk@4579 -
---
 packages/base/paszlib/gzio.pas  | 13 +++++++++++--
 packages/base/paszlib/zconf.inc |  1 +
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/packages/base/paszlib/gzio.pas b/packages/base/paszlib/gzio.pas
index 5660948f12..dc46d277c3 100644
--- a/packages/base/paszlib/gzio.pas
+++ b/packages/base/paszlib/gzio.pas
@@ -531,7 +531,6 @@ var
 
   s         : gz_streamp;
   start     : Pbyte;
-  next_out  : Pbyte;
   n         : cardinal;
   crclen    : cardinal;  { Buffer length to update CRC32 }
   filecrc   : cardinal; { CRC32 stored in GZIP'ed file }
@@ -539,6 +538,9 @@ var
   bytes     : integer;  { bytes actually read in I/O blockread }
   total_in  : cardinal;
   total_out : cardinal;
+{$ifndef pointer_arith}
+  next_out  : Pbyte;
+{$endif}
 
 begin
 
@@ -605,11 +607,15 @@ begin
 
     if (s^.z_err = Z_STREAM_END) then begin
       crclen := 0;
+    {$ifdef pointer_arith}
+      crclen:=s^.stream.next_out-start;
+    {$else}
       next_out := s^.stream.next_out;
       while (next_out <> start ) do begin
         dec (next_out);
         inc (crclen);   { Hack because Pascal cannot substract pointers }
       end;
+    {$endif}
       { Check CRC and original size }
       s^.crc := crc32(s^.crc, start, crclen);
       start := s^.stream.next_out;
@@ -639,13 +645,16 @@ begin
   end; {WHILE}
 
   crclen := 0;
+{$ifdef pointer_arith}
+  crclen:=s^.stream.next_out-start;
+{$else}
   next_out := s^.stream.next_out;
   while (next_out <> start ) do begin
     dec (next_out);
     inc (crclen);   { Hack because Pascal cannot substract pointers }
   end;
   s^.crc := crc32 (s^.crc, start, crclen);
-
+{$endif}
   gzread := integer(len - s^.stream.avail_out);
 
 end;
diff --git a/packages/base/paszlib/zconf.inc b/packages/base/paszlib/zconf.inc
index fe21025eae..316e1e0941 100644
--- a/packages/base/paszlib/zconf.inc
+++ b/packages/base/paszlib/zconf.inc
@@ -28,6 +28,7 @@
 
 {$IFDEF FPC}
  {$DEFINE Use32}
+ {$DEFINE pointer_arith}
  {$UNDEF DPMI}
  {$UNDEF MSDOS}
  {$UNDEF UNALIGNED_OK}  { requires SizeOf(ush) = 2 ! }