deconstify input buffer for iconv()

Unfortunately, the function iconv() wants a non-const input buffer. In this context, we only have a const pointer, which emits a correct gcc warning. Work around this ugliness with an union-deconst hack. This is optimized away in the binary. git-svn-id: https://svn.musicpd.org/mpd/trunk@7229 09075e82-0dd4-0310-85a5-a0d7c8717e4f

deconstify input buffer for iconv()
c011ab81 · Max Kellermann · Eric Wong · 51f5bf93 · c011ab81
Commit c011ab81 authored Apr 12, 2008 by Max Kellermann Committed by Eric Wong Apr 12, 2008
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Showing with 18 additions and 2 deletions

charConv.c src/charConv.c +18 -2

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--- a/src/charConv.c
+++ b/src/charConv.c
@@ -93,6 +93,22 @@ int setCharSetConversion(const char *to, const char *from)
 #endif
 }

+#ifdef HAVE_ICONV
+static inline size_t deconst_iconv(iconv_t cd,
+				   const char **inbuf, size_t *inbytesleft,
+				   char **outbuf, size_t *outbytesleft)
+{
+	union {
+		const char **a;
+		char **b;
+	} deconst;
+
+	deconst.a = inbuf;
+
+	return iconv(cd, deconst.b, inbytesleft, outbuf, outbytesleft);
+}
+#endif
+
 char *char_conv_str(char *dest, const char *string)
 {
 	if (!char_conv_to)
@@ -117,8 +133,8 @@ char *char_conv_str(char *dest, const char *string)
 			bufferPtr = buffer;
 			outleft = BUFFER_SIZE;
 			err =
-			    iconv(char_conv_iconv, &string, &inleft, &bufferPtr,
-				  &outleft);
+			    deconst_iconv(char_conv_iconv, &string, &inleft,
+					  &bufferPtr, &outleft);
 			if (outleft == BUFFER_SIZE
 			    || (err == (size_t)-1L && errno != E2BIG)) {
 				return NULL;