iconv() doesn't write to the data, just make compilers happy

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%402390

src/stdlib/SDL_iconv.c

@@ -28,6 +28,15 @@
 
 #ifdef HAVE_ICONV
 
+/* Depending on which standard the iconv() was implemented with,
+   iconv() may or may not use const char ** for the inbuf param.
+   If we get this wrong, it's just a warning, so no big deal.
+*/
+#if defined(_XGP6) || \
+    defined(__GLIBC__) && ((__GLIBC__ > 2) || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 2))
+#define ICONV_INBUF_NONCONST
+#endif
+
 #include <errno.h>
 
 size_t
@@ -36,19 +45,10 @@ SDL_iconv(SDL_iconv_t cd,
           char **outbuf, size_t * outbytesleft)
 {
     size_t retCode;
-#ifdef ICONV_REALLY_MODIFIES_INBUF
-    if (inbuf && *inbuf && inbytesleft) {
-        char *tmp = SDL_stack_alloc(char, *inbytesleft);
-        char *ptr = tmp;
-        SDL_memcpy(tmp, inbuf, *inbytesleft);
-        retCode = iconv(cd, &ptr, inbytesleft, outbuf, outbytesleft);
-        inbuf += (ptr - tmp);
-        SDL_stack_free(tmp);
-    } else {
-        retCode = iconv(cd, NULL, inbytesleft, outbuf, outbytesleft);
-    }
-#else
+#ifdef ICONV_INBUF_NONCONST
     retCode = iconv(cd, (char **) inbuf, inbytesleft, outbuf, outbytesleft);
+#else
+    retCode = iconv(cd, inbuf, inbytesleft, outbuf, outbytesleft);
 #endif
     if (retCode == (size_t) - 1) {
         switch (errno) {