Minor const correctness patch to SDL_iconv.

--HG--
branch : SDL-1.2
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/branches/SDL-1.2%402275

include/SDL_stdinc.h

@@ -561,17 +561,16 @@ extern DECLSPEC int SDLCALL SDL_vsnprintf(char *text, size_t maxlen, const char
 #define SDL_iconv_t     iconv_t
 #define SDL_iconv_open  iconv_open
 #define SDL_iconv_close iconv_close
-extern DECLSPEC size_t SDLCALL SDL_iconv(SDL_iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft);
 #else
 typedef struct _SDL_iconv_t *SDL_iconv_t;
 extern DECLSPEC SDL_iconv_t SDLCALL SDL_iconv_open(const char *tocode, const char *fromcode);
 extern DECLSPEC int SDLCALL SDL_iconv_close(SDL_iconv_t cd);
-extern DECLSPEC size_t SDLCALL SDL_iconv(SDL_iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft);
 #endif
+extern DECLSPEC size_t SDLCALL SDL_iconv(SDL_iconv_t cd, const char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft);
 /* This function converts a string between encodings in one pass, returning a
    string that must be freed with SDL_free() or NULL on error.
 */
-extern DECLSPEC char * SDLCALL SDL_iconv_string(const char *tocode, const char *fromcode, char *inbuf, size_t inbytesleft);
+extern DECLSPEC char * SDLCALL SDL_iconv_string(const char *tocode, const char *fromcode, const char *inbuf, size_t inbytesleft);
 #define SDL_iconv_utf8_ascii(S)		SDL_iconv_string("ASCII", "UTF-8", S, SDL_strlen(S)+1)
 #define SDL_iconv_utf8_latin1(S)	SDL_iconv_string("LATIN1", "UTF-8", S, SDL_strlen(S)+1)
 #define SDL_iconv_utf8_ucs2(S)		(Uint16 *)SDL_iconv_string("UCS-2", "UTF-8", S, SDL_strlen(S)+1)

src/stdlib/SDL_iconv.c

@@ -149,11 +149,12 @@ SDL_iconv_t SDL_iconv_open(const char *tocode, const char *fromcode)
 }
 
 size_t SDL_iconv(SDL_iconv_t cd,
-                 char **inbuf, size_t *inbytesleft,
+                 const char **inbuf, size_t *inbytesleft,
                  char **outbuf, size_t *outbytesleft)
 {
 	/* For simplicity, we'll convert everything to and from UCS-4 */
-	char *src, *dst;
+	const char *src;
+	char *dst;
 	size_t srclen, dstlen;
 	Uint32 ch = 0;
 	size_t total;
@@ -755,7 +756,7 @@ int SDL_iconv_close(SDL_iconv_t cd)
 
 #endif /* !HAVE_ICONV */
 
-char *SDL_iconv_string(const char *tocode, const char *fromcode, char *inbuf, size_t inbytesleft)
+char *SDL_iconv_string(const char *tocode, const char *fromcode, const char *inbuf, size_t inbytesleft)
 {
 	SDL_iconv_t cd;
 	char *string;