[Minor] Allow unconditional special handlers

contrib/libucl/ucl.h

@@ -1294,12 +1294,21 @@ typedef bool (*ucl_parser_special_handler_t) (struct ucl_parser *parser,
 		unsigned char **destination, size_t *dest_len,
 		void *user_data);
 
+/**
+ * Special handler flags
+ */
+enum ucl_special_handler_flags {
+	UCL_SPECIAL_HANDLER_DEFAULT = 0,
+	UCL_SPECIAL_HANDLER_PREPROCESS_ALL = (1u << 0),
+};
+
 /**
  * Special handler structure
  */
 struct ucl_parser_special_handler {
 	const unsigned char *magic;
 	size_t magic_len;
+	enum ucl_special_handler_flags flags;
 	ucl_parser_special_handler_t handler;
 	void (*free_function) (unsigned char *data, size_t len, void *user_data);
 	void *user_data;

contrib/libucl/ucl_parser.c

@@ -2862,8 +2862,9 @@ ucl_parser_add_chunk_full (struct ucl_parser *parser, const unsigned char *data,
 		memset (chunk, 0, sizeof (*chunk));
 
 		LL_FOREACH (parser->special_handlers, special_handler) {
-			if (len >= special_handler->magic_len &&
-					memcmp (data, special_handler->magic, special_handler->magic_len) == 0) {
+			if ((special_handler->flags & UCL_SPECIAL_HANDLER_PREPROCESS_ALL) ||
+					(len >= special_handler->magic_len &&
+					 memcmp (data, special_handler->magic, special_handler->magic_len) == 0)) {
 				unsigned char *ndata = NULL;
 				size_t nlen = 0;