[str.h] Fixing str_tokenizer_next

src/str.h

@@ -77,15 +77,15 @@ str_tokenizer_next(struct str_tokenizer *st)
 	struct str str;
 
 	if ( st == NULL ) {
-		goto ret_empty;
+		goto ret_err;
 	}
 
 	if ( st->cur >= st->str.size ) {
-		goto ret_empty;
+		goto ret_done;
 	}
 
 	if ( st->str.data[st->cur] == '\0' ) {
-		goto ret_empty;
+		goto ret_done;
 	}
 
 	str = st->str;
@@ -109,6 +109,16 @@ ret_empty:
 	str.data = "";
 	str.size = 0;
 	return str;
+
+ret_done:
+	str.data = "";
+	str.size = (size_t) -1;
+	return str;
+
+ret_err:
+	str.data = "";
+	str.size = (size_t) -2;
+	return str;
 }
 
 #endif /* defined(IMP) || defined(IMP_STR) */