textproc/sablotron: Modify iconv patch to support DragonFly

DragonFly 3.4 and DragonFly 3.6 have different iconv prototypes.
This modifies the FreeBSD support patch to handle the two different
DragonFly cases as well.

textproc/sablotron/files/patch-src__engine__encoding.cpp

@@ -1,11 +1,23 @@
---- ./src/engine/encoding.cpp.orig	2013-07-30 16:44:46.000000000 +0200
-+++ ./src/engine/encoding.cpp	2013-07-30 16:46:02.000000000 +0200
-@@ -278,7 +278,7 @@
+--- src/engine/encoding.cpp.orig	2003-11-21 08:45:11.000000000 +0000
++++ src/engine/encoding.cpp
+@@ -30,6 +30,7 @@
+  * GPL.
+  */
+ #include <errno.h>
++#include <sys/param.h>
+ 
+ #include "encoding.h"
+ #include "proc.h"
+@@ -278,7 +279,12 @@ eFlag Recoder::conv(Sit S, CDesc cd, con
              errno = 0;
              iconv((iconv_t)(cd -> physCD), 
  #               ifdef SABLOT_ICONV_CAST_OK
--                    (char**)(&inbuf),
++#if defined(__FreeBSD__) || \
++   (defined(__DragonFly__) && __DragonFly_version > 300502)
 +                    (const char**)(&inbuf),
++#else
+                     (char**)(&inbuf),
++#endif
  #               else
                      &inbuf,
  #               endif