anchor.diff:    inc(FSize, Count);
     FPosn := FSize;
     FBufPosn := FTail;
  -  Result := Count;
   end;
   {--------}
   function TAbBitBucketStream.Seek(const Offset : Int64; Origin : TSeekOrigin): Int64;
   var
  -  Posn : longint;
  +  Posn : Int64;
     BytesBack : longint;
   begin
   {$IFDEF LINUX}
  
positive.code: {--------}
  function TAbBitBucketStream.Read(var Buffer; Count : Longint) : Longint;
  var
    Chunk2Size : Int64;
    Chunk1Size : Int64;
    OutBuffer  : PByte;
  begin
    OutBuffer := @Buffer;
  
negative.code:       FBufPosn : longint;
        FPosn    : Int64;
        FSize    : Int64;
        FTail    : longint;
      protected
      public
        constructor Create(aBufSize : cardinal);
  