ccan: merge upstream base64 warning fixes

Author: jgriffiths

src/ccan/ccan/base64/base64.c

@@ -34,7 +34,7 @@ static int8_t sixbit_from_b64(const base64_maps_t *maps,
 	int8_t ret;
 
 	ret = maps->decode_map[(unsigned char)b64letter];
-	if (ret == '\xff') {
+	if (ret == (int8_t)'\xff') {
 		errno = EDOM;
 		return -1;
 	}
@@ -44,7 +44,7 @@ static int8_t sixbit_from_b64(const base64_maps_t *maps,
 
 bool base64_char_in_alphabet(const base64_maps_t *maps, const char b64char)
 {
-	return (maps->decode_map[(const unsigned char)b64char] != '\xff');
+	return (maps->decode_map[(const unsigned char)b64char] != (signed char)'\xff');
 }
 
 void base64_init_maps(base64_maps_t *dest, const char src[64])

src/ccan/ccan/base64/base64.h

@@ -118,7 +118,7 @@ ssize_t base64_decode_quartet_using_maps(const base64_maps_t *maps,
  * @note sets errno = EDOM if src contains invalid characters
  * @note sets errno = EINVAL if src is an invalid base64 tail
  */
-ssize_t base64_decode_tail_using_maps(const base64_maps_t *maps, char *dest,
+ssize_t base64_decode_tail_using_maps(const base64_maps_t *maps, char dest[3],
 				      const char *src, size_t srclen);
 
 
@@ -214,7 +214,7 @@ ssize_t base64_decode(char *dest, size_t destlen,
  * @note sets errno = EDOM if src contains invalid characters
  */
 static inline
-int base64_decode_quartet(char dest[3], const char src[4])
+ssize_t base64_decode_quartet(char dest[3], const char src[4])
 {
 	return base64_decode_quartet_using_maps(&base64_maps_rfc4648,
 						dest, src);